MINNEAPOLIS -- The Twins placed first baseman C.J. Cron back on the 10-day injured list with right thumb inflammation on Monday and optioned right-hander Zack Littell to Triple-A Rochester. Byron Buxton was also notably absent from Minnesota's roster moves, despite a successful full on-field workout at Target Field on Sunday.

Cron was activated from the IL last Tuesday following his recovery from the same injury, but he said the pain in the thumb did not subside as much as he had hoped while he was sidelined. Even as the thumb still bothered him, Cron went 4-for-19 with a homer, two doubles and four strikeouts in five games following his return.

"Power and driving the ball are a big part of my game, and it's hard to do with one hand," Cron said. "Hopefully, we can take care of this."

Cron did not appear in Sunday's series finale against the A's after receiving a cortisone injection in the thumb. He had not received injections during his first stint on the IL, but said that the medical staff wanted to be more proactive with the treatment this time around.

The thumb has been bothering Cron for more than a month. He hoped to make adjustments to accommodate the pain and play through it, but he did acknowledge that it was "pretty obvious" that he wasn't in a good condition and it would be better off in the long run for him to get the issue resolved now.

"We’re not trying to just get him out there on the field in a really uncomfortable state," manager Rocco Baldelli said. "I don’t think that accomplishes a lot where we’re at in the season right now."

Buxton worked out on the field again on Monday, and Baldelli said most of the concussion-like symptoms appear to have been resolved.

"Making sure that he is ready to go and confident and able to do all of the baseball activity is probably something we have to make sure of before we can activate him," Baldelli said. "I think he’s getting close."

Twins promote 2 arms for bullpen
In corresponding moves, the Twins brought up reinforcements for their bullpen by recalling left-hander Lewis Thorpe and selecting the contract of right-hander Cody Stashak from Rochester, bumping the 40-man roster up to 37 players.

Thorpe was called on right away, working 2 2/3 innings in the Twins' 8-6 victory Monday night. He picked up his first career win in the outing, allowing one run and four hits with two strikeouts.

The promotions of both Thorpe and Stashak brought Minnesota's bullpen back up to eight arms after the club had used a shorthanded relief corps for the first six games of the homestand against the Mets and A's. That proved problematic on Sunday, when Trevor May was stretched out for 49 pitches after Taylor Rogers, Blake Parker, Tyler Duffey and Littell had all been used heavily over the previous three games.

"If you're going to go with seven relievers, which you can do, you have to realize that at some point you're going to run into some sort of situation where you need to probably extend the bullpen a little bit, and then you're going to need some more length and maybe another person down there," Baldelli said. "So it's not overly surprising."

Though Littell had pitched effectively at the Major League level with a 1.50 ERA in 12 games following his conversion to a full-time relief role, he was optioned following Sunday's comeback win over the A's due to the need for fresh arms.

Stashak, 25, began the season with a 19-game stint in Double-A Pensacola before his promotion to Rochester, where he posted a 1.61 ERA with 31 strikeouts and four walks in 22 1/3 innings. He doesn't have overpowering stuff but relies on the action of his pitches to generate outs as he aggressively attacks the strike zone.

"He's efficient, and he knows what he's doing out there on the mound," Baldelli said. "He's able to execute. We anticipate him just coming here and continuing to do what he's been doing, because he's been doing a nice job."

The promotions of both Thorpe and Stashak brought Minnesota's bullpen back up to eight arms after the club had used a shorthanded relief corps for the first six games of the homestand against the Mets and A's. That proved problematic on Sunday, when Trevor May was stretched out for 49 pitches after Taylor Rogers, Blake Parker, Tyler Duffey and Littell had all been used heavily over the previous three games.

"If you're going to go with seven relievers, which you can do, you have to realize that at some point you're going to run into some sort of situation where you need to probably extend the bullpen a little bit, and then you're going to need some more length and maybe another person down there," Baldelli said. "So it's not overly surprising."

Though Littell had pitched effectively at the Major League level with a 1.50 ERA in 12 games following his conversion to a full-time relief role, he was optioned following Sunday's comeback win over the A's due to the need for fresh arms.

Stashak, 25, began the season with a 19-game stint in Double-A Pensacola before his promotion to Rochester, where he posted a 1.61 ERA with 31 strikeouts and four walks in 22 1/3 innings. He doesn't have overpowering stuff but relies on the action of his pitches to generate outs as he aggressively attacks the strike zone.

"He's efficient, and he knows what he's doing out there on the mound," Baldelli said. "He's able to execute. We anticipate him just coming here and continuing to do what he's been doing, because he's been doing a nice job."

Thorpe made his Major League debut on June 30 against the White Sox, when he allowed two runs in five innings with seven strikeouts, but saw his outing cut short at 70 pitches by an extended rain delay. The 23-year-old native of Australia is the No. 9 prospect in the Twins' organization, according to MLB Pipeline, and has a 5.02 ERA in 17 appearances -- 16 starts -- with the Red Wings in Triple-A this season, including 102 strikeouts in 84 1/3 innings.