His recovery is expected to last six weeks, which should give Cosart time to return to full strength before Spring Training.
The Padres acquired Cosart in July in the trade that sent Andrew Cashner to Miami. Cosart posted a 6.00 ERA in 13 starts this season, and he figures to be in the mix for a spot at the back end of the Padres' rotation in 2017.
Here's a rundown of a few other Padres injury updates:
• Right-hander Colin Rea is on schedule in his recovery from a partially torn ulnar collateral ligament. The Padres are hopeful he'll return to full strength before the end of the Arizona Fall League season. If he were, he'd pitch in a few games there. If not, the club is weighing whether to pitch Rea in a series of intensive live batting-practice sessions or send him to pitch a very brief stint in winter ball.
The Padres set a Dec. 1 deadline on Rea's return to full health. They're hopeful to avoid Tommy John Surgery, but if his recovery hits a snag, it may be the only course of action. Thus far, his bullpen sessions have been smooth.
• Right-hander Cesar Vargas, who missed the final four months of the season with a flexor strain in his right elbow, will pitch for Hermosillo in the Mexican Winter League. Vargas made just seven starts for the Padres, before going down with the injury in late May. Meanwhile, Cory Spangenberg (left quad tear) and Jabari Blash (left middle finger sprain) will soon report to the team's complex in Arizona. Once they've reached full health, they'll be re-evaluated before potentially heading out on winter ball stints.
• There's a decent possibility Carter Capps, who underwent Tommy John surgery on March 8, will be available for the Padres' 2017 opener. Capps -- a right-handed reliever who was acquired in the same trade that netted Cosart -- is ahead of schedule in his recovery and has been throwing aggressively for about a month.
AJ Cassavell covers the Padres for MLB.com. Follow him on Twitter @ajcassavell. This story was not subject to the approval of Major League Baseball or its clubs.