MINNEAPOLIS -- Right-hander Ervin Santana, who has struggled with velocity and results in five starts since returning from right middle finger surgery, was placed on the 10-day disabled list on Sunday and could miss the rest of the season, Twins manager Paul Molitor said. He's suffered recurring symptoms related to his original injury to his third finger MCP joint.
Reliever Alan Busenitz was recalled from Triple-A Rochester to take his spot on the roster, and lefty prospect Stephen Gonsalves was in the clubhouse and will take Santana's spot in the rotation to start on Monday against the White Sox in his Major League debut. Reliever Tyler Duffey was optioned to Triple-A Rochester to make room for Gonsalves on Sunday.
Additionally, outfielder Johnny Field was optioned to Rochester as outfielder Robbie Grossman was reinstated from the DL after missing 11 games with a strained right hamstring.
"It's a combination of some discomfort, and I don't think it's working quite as well," Twins manager Paul Molitor said of Santana's injury. "We all see how it's been going to this point. I'm not sure where it's going to go from here, but we just thought it made sense at this time rather than run him back out there on Tuesday. I don't know when the next time he'll pitch is going to be. We'll hopefully get another opinion on Tuesday."
Santana, 35, underwent the surgery on his right middle finger in early February but was expected to return in late April or early May. However, Santana dealt with complications, including a setback that forced him to wait until July to make his debut. His fastball velocity has been around 90 mph -- three mph less than last year -- and he's struggled with homers. His last start came on Thursday against the Tigers, when he allowed seven runs in four-plus innings, including three home runs.

"I have a little bit of discomfort right now, that's why we shut it down," Santana said. "Mostly the grip, that's where most of the pain is. You need to get it right before you do anything else. I'm going to shut it down and try to recover as fast as I can."
Santana is in the last year of his contract and the Twins aren't expected to pick up his $14-million option for next year. The 14-year veteran has a 3.68 ERA in 85 starts with Minnesota.
"It's our desire to try to find a way to support him the best way we can," Molitor said. "Sure, there's a component that what makes sense for us is going to be in there, too. He's well aware, we're well aware where he sits on next year status and all those type of things."
Gonsalves is the club's No. 5 prospect per MLB Pipeline. He's gone a combined 12-3 with a 2.76 ERA between Double-A Chattanooga and Triple-A Rochester this season. He's struck out 95 and walked 55 in 100 1/3 innings with Rochester this season.

"I was actually struggling a little bit walking everyone," Gonsalves said. "I was effectively wild, not mixing in a whole lot of hits. I've missed bats in the past with good changeups and good spin. Hopefully, we can just go from there."
Gonsalves, 24, said he found out late Saturday he was going to make his MLB debut, and the first person he called was his grandmother.
"I shared some tears with her," Gonsalves said. "We're all very excited. My grandfather passed away three years ago, and I dedicated this season to him. They'd been at every game ever since I was a little kid. They had season tickets to the Padres when my dad was a kid. Big sports fans. Big baseball fans. She was number one."
Busenitz, who pitched in 11 games over three stints with the Twins this season, recently appeared in seven games for the Red Wings, allowing six runs on nine hits in eight innings pitched with three saves.
Grossman and Busenitz will take the vacated 25-man roster spots of Field and Santana.