The Royals have lost left-hander Matt Strahm for the season, and they may have lost right-hander Nate Karns as well, a Royals official confirmed Friday night.

Strahm, 25, underwent surgery to repair a torn patellar tendon in his left knee on Friday and will be out for the remainder of 2017, Royals vice president of communication Mike Swanson said. Strahm had been on the 60-day disabled list.

"Our mindset is, you just move on," manager Ned Yost said. "You can't dwell on it. He [Matt] was a pretty important piece in our bullpen and we've got two strong lefties down there with [Mike] Minor and [Scott] Alexander. [Neftali] Feliz has been throwing the ball well, he'll pick up the slack. So every team deals with injuries, you just got to deal with it and move on."

Strahm left last Saturday's game with knee soreness and was placed on the disabled list, then was shifted to the 60-day disabled list earlier this week.

Karns (2-2, 4.17 ERA) apparently has shown symptoms of thoracic outlet syndrome, the same ailment that afflicted former Royals Luke Hochevar, Dillon Gee and Christopher Young, as well as Royals prospect Kyle Zimmer.

Karns will see TOS specialist Dr. Robert Thompson in St. Louis in the near future for further examination, Swanson said. Karns was put on the disabled list in mid-May with forearm soreness. His recovery was slow and the Royals eventually put him on the 60-day disabled list.