MINNEAPOLIS -- Blake Parker was the latest Twins reliever designated for assignment on Wednesday as Minnesota's bullpen remained in a significant state of flux ahead of the July 31 Trade Deadline.

The Twins have now designated for assignment four relievers in the past two weeks. Adalberto Mejia was the first to go, on July 13, followed by Mike Morin on July 16, Matt Magill on Thursday and now Parker.

Kohl Stewart was also on the move, optioned back to Triple-A Rochester. In corresponding moves, left-hander Devin Smeltzer was recalled from the Red Wings, and the contract of 36-year-old right-hander Carlos Torres was selected, keeping the Twins' 40-man roster at 37 players.

"Very challenging situation," manager Rocco Baldelli said. "[Parker] is certainly a loved figure in the locker room. He's a guy that holds the respect of every person here. He is a good Major League pitcher and just a wonderful human being. So very difficult times here in some ways. We're excited to have the guys that we've called up here, but it was very tough for Blake."

The 34-year-old Parker was the Twins' only relief acquisition during the offseason when he was signed to a one-year, $1.8 million contract. He posted a 4.21 ERA with 34 strikeouts and 16 walks in 36 1/3 innings for the Twins. He began the season as the Twins' primary closer but was moved into earlier innings as the season progressed.

He only allowed two earned runs in 17 1/3 innings across his first 18 appearances, with eight saves and four holds, but struggled to a 7.11 ERA in his final 19 games with the Twins. His strikeout, walk and home run rates were among the worst of his career. His final appearance came on Tuesday night, when he was charged with four earned runs on three hits in one-third of an inning against the Yankees.

In the aftermath of the move, the next men up to join the rotating back end of the bullpen are Smeltzer, one of the members of the starting rotation at Rochester, and Torres, a veteran of 10 Major League seasons who appeared in four games for the Tigers this season.

Torres had a 2.79 ERA in 28 Triple-A appearances this season with 42 strikeouts and 18 walks in 48 1/3 innings, spanning stints with El Paso (Padres), Toledo (Tigers) and Rochester.

"He's a good, experienced arm," Baldelli said. "A guy that we're going to be able to put in different roles. I think the important thing is that he's going to be able to fill different spots for us and we don't have to worry about the experience factor. We don't have to worry about putting him in a position he hasn't really been in before."

Buxton update should come in Chicago
Byron Buxton will travel with the Twins on their upcoming road trip through Chicago and Miami, and Baldelli did not expect that the center fielder would need a rehab assignment before his return from the injured list. Baldelli expected that the Twins would announce a further development to Buxton's situation in Chicago.

Buxton has been sidelined since July 14 with concussion-like symptoms after he hit his head on the ground while making a diving catch.

"I think he's pretty confident right now in how he's feeling," Baldelli said.