Clarke (hamstring) could begin a rehab assignment with Triple-A Las Vegas as soon as Tuesday, Martin Gallegos of MLB.com reports.
Clarke has been shelved since April 22, first due to a bone bruise in his right foot, then due to a strained left hamstring that he sustained during a rehab game in late May. With the center fielder wrapping up his running progression at the Athletics' training complex in Arizona, he's nearing a return to game action. The Athletics are likely to give Clarke an extended rehab assignment to get back in a rhythm, putting his potential return to the big-league club around the end of August or beginning of September.