When the short-on-starters Twins summoned Simeon Woods Richardson from St. Paul in late April, they weren't exactly sure what they were getting or how long it might last. But the rookie righthander helped salvage their season, never missing a start and pitching well for long stretches.

His season ended Thursday.

With his velocity down, his final game the shortest and least effective start of his season and no plausible role in the playoffs, the Twins made the perfectly logical, if cold-blooded, decision to remove Woods Richardson from their roster. Technically, he was optioned back to the Class AAA Saints, though their season has ended, just like his.

"He stepped up and showed up when we needed him. We absolutely needed him, and he came in and just kept pitching well," Twins manager Rocco Baldelli said. "He took full advantage of the opportunity. We ask our guys to compete and he did. The body of work was very good."

Woods Richardson finishes his first full major league season with a 5-5 record and 4.17 ERA in 28 starts; his 18 no-decisions were the most by any starter in the game. He struck out 117 batters, through he led the Twins in walks by issuing 48.

"I'm extremely happy with myself. It's a true testament to all the hard work we put in," said Woods Richardson, who turns 24 on Friday. "Doing my job and trying every day to give the team a chance to win, that's what I was trying to do all year."

He was better at it early in the year than late, perhaps because his 147 innings at two levels, including 133 in the big leagues, were by far the most he has ever pitched. He posted a 3.27 ERA in his first 17 starts of the year, holding hitters to a .224 average with a 3-to-1 strikeout/walk ratio of 76 to 25.

But he wasn't the same after the All-Star break, with a 5.91 ERA in 11 starts, and batters posting a .284 average. He struck out 41 and gave up 23 walks. Woods Richardson started Wednesday's game against the Marlins, faced 10 batters and retired only three.

Baldelli, though, expects Woods Richardson to be even better next season.

"Seeing the steps he's taken, I don't think it's crazy at all to see him improve and watch what might come next. Several things improved off of last year. What can he do going forward?" Baldelli said. "There will always be things to [improve upon], and he's not afraid to attack them. He's not afraid of constructive criticism. It's a great sign from a young pitcher."

Sands has MRI

After feeling something unusual in his left knee on Wednesday, righthander Cole Sands underwent a magnetic resonance imaging test Thursday.

The diagnosis: "A very mild sprain," Baldelli said. "There's some tightness back there. Not enough to make it whatever the lowest grade of strain is."

Sands — who has been one of the Twins' best relievers, going 9-1 with a 3.04 ERA and four saves — believes he can still pitch, though, so he was not put on the injured list. He then proved it by pitching the 10th inning against the Marlins.

"Just the back side of the knee. It started when I was warming up in the pen," Sands said. "It wasn't anything terribly bad, but it was enough to change some of my mechanics. So I just had to push through it."

Etc.

• Catcher Jair Camargo was recalled from St. Paul to take Woods Richardson's spot, after the Twins gave Christian Vázquez permission to be leave the team for a day to deal with an unspecified family situation.

• Righthander Chris Paddack threw a live bullpen session Thursday morning and said he was "feeling great" afterward. The Twins will meet with him Friday to discuss whether to activate him for the weekend's final series.