The Royals expect Moustakas to recover in time for Spring Training in 2017.
Moustakas injured his knee during a May 22 collision with teammate Alex Gordon while chasing a foul ball.
Young gets the nod
Right-hander Chris Young will start on Sunday in place of right-hander Dillon Gee, who was optioned to Triple-A Omaha.
Young, who recently came off the disabled list (strained forearm), has pitched four scoreless innings since his return.
"He's got life on his fastball again," Yost said.
Medlen to Arizona
Right-hander Kris Medlen, on the disabled list with a strained rotator cuff, continues his recovery and will have two more side sessions in Kansas City before being sent to the Royals' Spring Training site in Arizona for further rehab.