The 29-year-old Moore signed with the Tigers in the offseason and did not allow a run in 10 innings this year, but he hurt his knee April 6 while trying to field a bunt.
Moore said last weekend he had a tear in his meniscus, but the severity wasn't clear. Manager Ron Gardenhire provided more information on Wednesday.
"He had the surgery, and they had to fix some things up in there, and he's out for the year,'' Gardenhire said.
Moore was an All-Star in 2013 with the Tampa Bay Rays, but Tommy John surgery cost him almost all of 2014, and he hasn't been very effective since. He signed a $2.5 million, one-year contract with Detroit. That deal included an extra $1 million in performance bonuses, but none of those kicks in until his 10th start.
"He was making a great comeback with us, throwing the ball really well, had a great spring and we were excited -- and now he's going to miss a season," Gardenhire said. "Him and his family, that's very frustrating, so our thoughts go to him.''
Dr. Keith Meister performed the operation on Wednesday.
"He got in there and fixed what he saw,'' said Doug Teter, Detroit's head athletic trainer. "The rehab coming back for what he had to do to repair it is not the timeline we were hoping for.''
Detroit also is without right-hander Michael Fulmer, who is out for the season following an elbow injury.