Affirmed in part and dismissed in part by published opinion. Judge WILLIAMS wrote the majority opinion, in which Judge WILKINS joined. Judge ELLIS wrote a separate opinion concurring in part and concurring in the result.
OPINION
WILLIAMS, Circuit Judge:Joseph Ben Speed, Jr., appeals the sentence imposed by the district court following his conviction for conspiracy to possess with intent to distribute cocaine in violation of 21 U.S.C.A. § 846 (West Supp.1994). Specifically, Speed maintains that the district court committed reversible error in denying his motion to continue sentencing pending a determination by the Government whether, due to Speed’s substantial assistance, it would move for a downward departure under the Sentencing Guidelines, pursuant to U.S.S.G.1 § 5K1.1. Furthermore, in a related argument, Speed maintains that the district court sentenced him in violation of the law because it did not fully take into consideration Speed’s assistance to the Government. For the reasons that follow, we affirm the district court’s denial of Speed’s motion for continuance of sentencing and dismiss the appeal to the extent that Speed argues the district court imposed his sentence in violation of the law.
I.
On September 21,1993, a grand jury in the Eastern District of North Carolina returned an indictment against Speed, Patrick Sidney, Larry Hobgood, and Colonel Hunt, charging the four with conspiracy to possess with intent to distribute cocaine in violation of 21 U.S.C. §§ 841(a)(1), 846. On November 22, 1993, Speed pled guilty to the conspiracy charge pursuant to a negotiated plea agreement.
On March 8, 1994, the district court held a sentencing hearing for Speed. At that hearing, the district court considered a motion from Speed to continue the sentencing until the Government determined whether it would file a motion for downward departure for substantial assistance, pursuant to U.S.S.G. § 5K1.1, based on information Speed provided to help the Government in other criminal investigations. After taking argument, the district court denied the motion for a continuance and sentenced Speed to 115 months imprisonment, the high end of the applicable Sentencing Guideline range. Speed appeals from the sentence he received pursuant to a provision in his plea agreement that provided a right of appeal if the sentence imposed was greater than 63 months.
II.
A.
Speed’s primary argument on appeal is that the district court committed reversible error in denying his motion for a continuance of the sentencing hearing. A district court’s decision to grant or deny a motion for continuance is reviewed for an abuse of discretion. United States v. Attar, 38 F.3d 727, 735 (4th Cir.1994) (citing Morris v. Slappy, 461 U.S. 1, 11, 103 S.Ct. 1610, 1616, 75 L.Ed.2d 610 (1983)). Because a district court has broad discretion in scheduling the sentencing proceeding, “[a]bsent a showing both that the denial was arbitrary and that it substantially impaired the defendant’s opportunity'to secure a fair sentence, we will not vacate a sentence because a con*645tinuance was denied.” United States v. Booth, 996 F.2d 1395, 1397-98 (2d Cir.1993) (quoting United States v. Prescott, 920 F.2d 139, 146-47 (2d Cir.1990)). In reviewing the district court’s denial of a motion for continuance in a criminal proceeding, we remain cognizant of possible Sixth Amendment implications concerning the ability of counsel for the defendant to provide effective assistance. United States v. LaRouche, 896 F.2d 815, 822-25 (4th Cir.) (Sixth Amendment analysis of denial of continuance requires looking at whether abuse of discretion took place and possible prejudice to defendant), cert. denied, 496 U.S. 927, 110 S.Ct. 2621, 110 L.Ed.2d 642 (1990).
In support of his motion for a continuance, Speed argues that the district court should have ^delayed his sentencing because the Government interviewed him concerning his knowledge of other criminal matters and, at the time of sentencing, had not yet decided whether to call him as a witness in future criminal cases. According to Speed, the likelihood that the Government would file a motion for downward departure would increase dramatically if it decided to call him as a witness at other trials. By continuing the sentencing for an unspecified amount of time, the district court would provide the Government and Speed with the proper opportunity to gauge the level of Speed’s assistance.
Although in some circumstances delaying a defendant’s sentencing might be advantageous to all parties and would not unacceptably consume scarce judicial resources, we can find no indication in the record that this is one of- those times. In his motion and at oral argument before the district court, Speed gave no estimate of the length of his requested continuance or when any possible trials at which he would testify for the Government would take place. In addition, we note that the plea agreement explicitly stated that the Government had no duty to file a motion for downward departure based upon Speed’s substantial assistance, whether at sentencing or at any other point. Without more, Spéed has failed to provide a basis upon which we can find an abuse of discretion on the part of the district court. See Booth, 996 F.2d at 1397.
Speed also argues that the district court was incorrect in noting that ‘a motion for reduction of sentence for substantial assistance, filed under Fed.R.Crim.P. 35(b),2 subsequent to sentencing would- sufficiently protect his interest. Because a downward departure granted pursuant to Fed. R.Crim.P. 35(b) can only apply to substantial assistance that takes place after sentencing, Speed correctly maintains that his actions before sentencing could not be taken into account as substantial. assistance. United States v. Martin, 25 F.3d 211, 215-16 (4th Cir.1994) (“Fed.R.Crim.P. 35(b) grants the sentencing judge the authority to reduce a defendant’s sentence only for substantial assistance rendered subsequent to sentencing”) (emphases in original); United States v. Francois, 889 F.2d 1341, 1345 (4th Cir.1989), cert. denied, 494 U.S. 1085, 110 S.Ct. 1822, 108 L.Ed.2d 951 (1990).3 Thus, Speed ar*646gues that he would be unacceptably prejudiced by the denial of the continuance because a Rule 35(b) motion could not adequately account for his pre-sentencing assistance in this case. We disagree. If the Government’s decision to move for a downward departure would turn primarily on Speed’s future testimony at other criminal proceedings, as are all the indications in the record, then the district court did not abuse its discretion in reasoning that a -Rule 35(b) motion for downward departure would be an appropriate method by which to account for Speed’s possible future assistance to the Government.
Speed also complains that the Rule 35(b) mechanism is unacceptably cumbersome because it forces defense attorneys, especially' those appointed by the district court, to monitor continually the defendant’s progress towards rendering substantial assistance. Aside 'from the fact that we are not in the position to change the meaning of clear procedural rules such as Rule 35(b) to correct their potentially cumbersome nature, Speed’s argument has no merit in its application to this case. It is clear from the facts before us that the Government’s decision to file a downward departure for substantial assistance would turn ■ on Speed’s possible future testimony. Therefore, it is not too onerous a task in a continuing attorneyrdient relationship for counsel occasionally to check whether the Government has called Speed as a witness. Furthermore, there is little question that Speed will have great incentive to keep his counsel apprised of his status.
Speed also argues that the denial of the motion for continuance was prejudicial because the Government had promised in the plea agreement that it would inform the district court of the extent to which Speed had assisted the Government up to the time of sentencing. The difficulty faced by Speed on this point, however, is that he has never maintained, either before the district court or on appeal, that the Government breached the plea agreement with him. See, generally, United States v. Conner, 930 F.2d 1073, 1076-77 (4th Cir.), cert. denied, 502 U.S. 958, 112 S.Ct. 420, 116 L.Ed.2d 440 (1991). We decline Speed’s invitation to guess about the possible breach of a plea agreement when Speed is unwilling to argue that a breach has actually occurred. See United States v. Robertson, 40 F.3d 1046, 1048 (9th Cir.1994) (“A claim of breach of the plea agreement ... is the sort of claim which a defendant ordinarily will recognize immediately and should be required to raise when the alleged- breach can still be repaired.”).
Accordingly, without any compelling reason for delaying the proceedings, the district court did not abuse its discretion in denying the motion for a continuance.
B.
Speed makes an additional argument that turns in large part upon the argument we have rejected concerning the motion for a continuance: that the district court sentenced him in violation of the law because, but for the district court’s failure to grant the motion for continuance, it would not have exercised its discretion to sentence him at the high end of the Sentencing Guidelines based upon the offense committed and his criminal history.4 Speed points out, once again, that in his plea agreement the Govern*647ment promised to apprise the district court as to the full extent of Speed’s cooperation at sentencing. According to Speed, the sentence imposed by the district court violated the law because the Government did not summarize the full extent of aid offered by Speed up until that point.
Speed’s argument concerning the failure to grant the motion for a continuance fairs no better when repackaged as a violation of the law by the district court under 18 U.S.C. § 3742(a)(1). When an adjudged sentence falls within a properly calculated guideline range, appellate review is not permitted. United States v. Porter, 909 F.2d 789, 794 (4th Cir.1990). At sentencing, the district court reasoned that Speed’s lengthy 'criminal record warranted a sentence at the high end of the applicable guidelines range. Absent evidence that the Government breached the plea agreement, this Court will not review a sentence imposed within the correct guideline range. We therefore affirm this portion of Speed’s appeal. 18 U.S.C. § 3742(f)(3).
III.
For the reasons stated, we affirm the opinion of the district court.
AFFIRMED IN PART AND DISMISSED IN PART.
. United States Sentencing Commission, Guidelines Manual (Nov. 1993).
. Rule 35(b) states, in relevant part:
(b) Reduction of Sentence for Changed Circumstances. The court, on motion of the Government made within one year after the imposition of the sentence, may reduce a sentence to reflect a defendant’s subsequent, substantial assistance in the investigation or prosecution of another person who has committed an offense, in accordance with the guidelines and policy statements issued by the Sentencing Commission pursuant to section 994 of title 28, United States Code. The court may consider a government motion to reduce a sentence made one year or more after imposition of the sentence where the defendant's substantial assistance involves information or evidence not known by the defendant until one year or more after imposition of sentence. The court's authority to reduce a sentence under this subsection includes the authority to reduce such sentence to a level below that established by statute as a minimum sentence.
. Judge Ellis raises some noteworthy concerns in his concurrence as to our holding that pre-sen-tencing assistance may not be taken into account in a Rule 35(b) motion. While we might find Judge Ellis's reasoning more persuasive if we were writing on a clean slate, we feel bound by our precedent as established in Martin and Francois. Unless or until that precedent is altered by en banc review or by revision of Rule 35(b), as Judge Ellis suggests at the end of his concurrence, we must follow that precedent.
Additionally, we note our disinclination to agree with Judge Ellis’s reliance on United States *646v. Drown, 942 F.2d 55 (1st Cir.1991), for the proposition that "the First Circuit has explicitly recognized that a court may, consider the full extent of a defendant’s assistance in ruling on a Rule 35(b) motion." A review of Drown reveals that the. First Circuit was confronted with the same issue as this Court in Martin: whether the government may predicate its decision to defer a U.S.S.G. § 5K1.1 motion on the fact that it will make a Rule 35(b) motion after sentencing? Both courts answered this question in the negative. However, to the extent that the Drown court took the position in a footnote that a sentencing court could take pre-sentencing assistance into account on a Rule 35(b) motion, the holding is not a model of clarity. Drown, 942 F.2d at 59 n. 7 The footnote not only lacks any citation to cases or Rule 35(b) to support its position, but also appears to have been dictum. Accordingly, after considering the footnote in Drown, we remain constrained by our precedent.
. The district court calculated a total offense level of 23 and a criminal history category of VI. Accordingly, the guideline range applicable to Speed at sentencing was 92 to 115 months. See United States Sentencing Commission, Guidelines Manual, Ch. 5 Pt. A (Nov.1993). The district court sentenced Speed to 115 months imprisonment.