USA's chances of reclaiming the Auty Cup from Canada this week have been dealt a serious blow after fast bowler Ali Khan had to withdraw from the squad due to an injury picked up during the team's five-day training camp in Indianapolis last month.

Khan, 25, played for Guyana Amazon Warriors in the Caribbean Premier League this summer, and was in line to make his USA debut. But he suffered a left hamstring strain during a fitness and agility test on September 20. Khan had injured himself while doing a drill that required the players to complete a simulated three-run sprint between the wickets for which they were timed.

Although the initial prognosis was that Khan would be fit in time for this week's matches against Canada, he has not been cleared to play. USA's team management decided to give him two more weeks to recover, ahead of the WCL Division Four, which is scheduled to start on October 29.

Hammad Shahid has been drafted in as a replacement for Khan, and is also on standby for WCL Division Four if Khan is unable to recover in time. Shahid, 24, is based in Los Angeles, where the Auty Cup and WCL Division Four will be held. He was USA's leading pace bowler at the World T20 Qualifier in Ireland last summer, with seven wickets in six games. He was also in the ICC Americas combined squad that played in the WICB Nagico Super50 in January this year.

Peter Della Penna is ESPNcricinfo's USA correspondent. @PeterDellaPenna