Clarke recently underwent surgery to remove a loose body from his left elbow.
Clarke had been slated to play in the Arizona Fall League, but he'll have to rehab instead. The southpaw is expected to be recovered in time to pitch in instructional camp in January. It's the second surgery in less than a year for Clarke, who had an operation in January to address an aneurysm in his left arm. In between those two procedures, the lefty held a 3.34 ERA and 44:17 K:BB over 29.2 innings across four minor-league stops, showcasing his electric stuff but also his control issues.