MINNEAPOLIS -- Zack Littell was recalled from Triple-A Rochester for the first time this season before Friday's series opener against the White Sox, and he's hoping that a new split-fingered changeup and his previous MLB experience can help spur his continued development at the Major League level.

The 23-year-old Littell had a 6.20 ERA in eight appearances (two starts) in his first taste of the big leagues last season, with 14 strikeouts and 11 walks in 20 1/3 innings.

Littell impressed during the Twins' 11-4 win over Chicago, closing the victory with two perfect innings, striking out two.

During Spring Training, Littell said he sat down with Twins pitching coach Wes Johnson and developed a plan to not only tweak his mechanics but also make targeted developments to all of his pitches. Littell has worked this season to improve the carry on his fastball and add depth to his curveball and slider.

"The development that we're doing, even up here now, it's really helped, from pitch development to some mechanical tweaks we've been making," Littell said. "Obviously, [Johnson], [assistant pitching coach Jeremy Hefner], [Triple-A bullpen coach] Mike McCarthy, [Triple-A pitching coach Stu Cliburn], all those guys, the communication has been great. What we're trying to do with each pitcher is very individualized and it's been really good to continue that development."

But the most dramatic change came with his changeup, which he switched over to a split-fingered grip similar to the one Jake Odorizzi uses and made a focus of his preparation this season. Littell said the new grip helps him throw the changeup for strikes more effectively in all counts, and he worked on it in earnest after Johnson showed him the advanced data that suggested it could be a particularly effective offering.

"The changeup is a vastly underrated pitch," Littell said. "Everybody in baseball, especially right-on-right, left-on-left, it's being underused. Last year, I knew it was a small sample size, but the numbers on right-on-right changeups were incredible. I think that kind of prompted me to really kind of dive into the changeup development and make it a weapon, especially to right-handed hitters, but to both."

Littell admits that his consistency with the pitch is still developing on a day-by-day basis, but he feels much more comfortable now, as a whole, than he did at the start of the season.

That's been reflected in his Triple-A numbers this year: After starting the season with eight earned runs allowed, including three homers, in his first two appearances, he has yielded 12 earned runs across his last six starts. He has a 4.19 ERA and 45 strikeouts in 43 innings for Rochester this season.

"We are in a spot where we definitely could add a good arm to the bullpen," Twins manager Rocco Baldelli said. "That would be helpful. It would certainly allow us to go into today’s game, tomorrow’s game, a little bit more comfortably. But like we’ve seen with a bunch of our guys already, that doesn’t mean he’s just here to prepare to pitch in length. He could find himself in different spots for sure."

In a corresponding move, reliever Austin Adams was designated for assignment. Adams made two appearances with the Twins after his contract was selected from Rochester on May 16. He allowed three hits, three walks and five earned runs, including a Tommy La Stella grand slam, in the ninth inning of what had been a 16-2 blowout win on Friday in Anaheim.

When a player's contract is designated for assignment -- often abbreviated "DFA" -- that player is immediately removed from his club's 40-man roster. Within seven days of the transaction (had been 10 days under the 2012-16 Collective Bargaining Agreement), the player can either be traded or placed on irrevocable outright waivers.

Injury updates

• Nelson Cruz (left wrist strain), who traveled to Seattle and Anaheim with the team, took swings again on Friday and said that he felt good following his session. Baldelli did not commit to a timeline for Cruz's activation, but chief baseball officer Derek Falvey previously said he expected Cruz to come off the injured list "soon after" Friday.

• Mitch Garver (high left ankle sprain) has responded well to swinging and running and has shown a good range of motion as he has continued to "progress pretty rapidly" and without much swelling from the sprain, which was sustained during a home-plate collision with Shohei Ohtani on May 14.

"He's responded well to pretty much everything we've thrown at him so far," Baldelli said. "As a catcher, we want to make sure that he's fully capable of the workload before we make a statement like, 'We are going to bring him back.' We want to test that out and make sure that's going to go well too. Everything so far has been pretty solid."