MINNEAPOLIS -- Twins manager Paul Molitor announced on Tuesday that the club will lose two starting pitchers for the remainder of the season, as right-hander Michael Pineda was diagnosed with a slight meniscus tear in his right knee and lefty Adalberto Mejia is still dealing with a nerve issue near his left wrist.
Pineda, who is coming off Tommy John surgery in July of 2017, was nearing a return to the Majors but felt discomfort in his knee while throwing a bullpen session with Triple-A Rochester last week. He returned from his rehab assignment to see team doctors in Minnesota over the weekend and underwent an MRI exam that revealed the injury.
"There's speculation, at least in the early stages, that it's an old injury that has begun to show up symptomatically in terms of pushing off that back leg," Molitor said. "Hopefully, over the next couple of days, our doctors and other people will be involved in decisions about options he has in terms of trying to overcome that. Obviously, some of them require procedures."
The Twins are hopeful Pineda will avoid surgery, but he'll miss the rest of the season either way. The 29-year-old had made four rehab appearances with the Gulf Coast League Twins, Class A Advanced Fort Myers and Triple-A Rochester, posting a 1.50 ERA with nine strikeouts and three walks in 12 innings. He was scheduled to start on Sunday with Rochester before the injury.
Pineda was signed to a two-year, $10 million deal before the season with the Twins knowing he'd only be able to contribute in September and focusing more on 2019, when he'll earn $8 million. The good news is it's not an injury related to his Tommy John rehab.
"It's been a productive year in his coming back from his surgery," Molitor said. "The biggest goal will be to try to figure out how to give him as much of the offseason as we can to be somewhat normal in preparing for next spring. Because we have pretty high confidence that we'll be in good shape. But in the short term here, find out what we need to do and start getting after it."
Mejia, meanwhile, has been out since Aug. 7 with what was originally diagnosed as a wrist strain before further tests revealed the nerve issue. He wasn't likely to return, and Molitor confirmed it on Tuesday. He finished his 2018 campaign with a 2.01 ERA in five appearances (four starts), throwing 13 straight scoreless innings to end his season.

"We're going to monitor his progress," Molitor said. "But they think with that nerve traction that it's going to take more time than what we have left to let the thing get calmed to the point where we feel confident to have the ball in his hand."
Molitor said he's currently planning how the rotation will look the rest of the way, and it's likely the Twins will go to a six-man rotation in September, especially to ease the workload of young pitchers such as Stephen Gonsalves and Kohl Stewart. They're also still considering tinkering with an opener, a reliever used to start a game before handing it over to a traditional starter, like the Rays have done this season.
"We've mapped out a few ways we're thinking about going in September in terms of trying to not only see more people and keep some of these guys in here who've had a couple of starts," Molitor said. "We haven't inked it in, but we're looking at different scenarios on how to proceed. Pineda being taken out of the equation has changed it a little bit."
Polanco out, expected back Wednesday
Shortstop Jorge Polanco, who left Sunday's game with general cramping in both legs, was held out of the starting lineup on Tuesday for precautionary reasons. Ehire Adrianza started at shortstop in his absence, but Polanco expected to return Wednesday.

"He's doing a lot better," Molitor said. "We kind of stuck with our original plan coming out of Sunday, to plan for an extra day just to make sure we can get him back to not having to worry about any tightness or cramping or whatever it was that kind of was affecting him on Sunday. I'm not sure what was the source of it, other than the fact he was having trouble keeping his legs loose. The last thing you want to do is put yourself in position to push it too far, and you end up pulling something and you lose a lot of time."