HOUSTON -- The Twins recalled Kohl Stewart and Fernando Romero from Triple-A Rochester on Wednesday morning as they reinforced their pitching staff by expanding to 13 pitchers after using a deeper bench through the first month of the season. In corresponding moves, reliever Tyler Duffey and outfielder Jake Cave were optioned to Rochester.

Both Stewart and Romero appeared in the Twins' 7-1 loss to the Astros on Wednesday. Stewart allowed five runs over six innings, while Romero gave up a two-run home run in his two innings.

After the game, the Twins announced that Stewart had been sent back to Triple-A. Minnesota is expected to make a corresponding roster move at some point before Friday’s game against the Orioles. Right-handed reliever Matt Magill, who has eight strikeouts and one walk across five appearances in his rehab assignment with Rochester, could be an option to be reinstated from the injured list to reinforce the bullpen.

Stewart, a Houston native, started Wednesday night's series finale against the Astros at Minute Maid Park. He had a 3.68 ERA in eight appearances for the Twins last season -- all as a starter or as the "primary pitcher" following an opener -- including five scoreless innings at Minute Maid Park on Sept. 4. He was 1-2 with a 6.00 ERA in three Triple-A starts this season.

The Twins needed a fresh starter after Friday's postponement due to rain in Baltimore. Jose Berrios then had to pitch in Saturday's doubleheader and wasn't available to start on Wednesday, as previously scheduled.

Because Minnesota is currently in a stretch of 39 games in 40 days, including the doubleheader in Baltimore, it appeared to be only a matter of time before the Twins would expand their pitching staff to ease the burden on the bullpen. The club has adjusted its roster composition to fit its schedule throughout the season, carrying only 11 pitchers on Opening Day before expanding to 12 in mid-April and now the full complement of 13 arms.

"We've been going with a pitcher short in the bullpen for a while, and we're probably in a stretch right now where it makes sense for us to carry another arm for a lot of different reasons," Minnesota manager Rocco Baldelli said. "For some protection reasons and to take care of the other guys that are out there and have been pitching a lot, I think we needed to also carry that arm."

Romero had been optioned to Triple-A to begin the season after experiencing command issues in Spring Training, but he appeared for the Twins on Saturday as the 26th man for the doubleheader. The hard-throwing 24-year-old allowed three earned runs, including a homer, in two innings during that relief appearance.

Romero allowed four earned runs in 8 1/3 innings in Rochester this season, though his command appeared to have improved, as he struck out 11 while walking only two.

Duffey allowed five runs (one earned), including two homers, in his four appearances for the Twins after he was recalled from the Minors on April 16. He threw 37 pitches on Tuesday night against the Astros, allowing four late unearned runs in the Twins' blowout loss.

Cave had hit .233/.324/.267 in 34 plate appearances across 12 games this season as the Twins' fourth outfielder. Though Cave brought solid outfield defense and power potential to the lineup, he had remaining Minor League options, unlike backup infielder Ehire Adrianza. The versatility of Adrianza, Willians Astudillo and Marwin Gonzalez should still leave the Twins adequately covered in the outfield in Cave's absence.

"[Cave is] a guy that is in a situation right now where he's not getting the at-bats as a young player that he needs," Baldelli said. "He needs to play. ... General statement, but he needs to get some at-bats in, and as of right now, he's not going to get them on a regular basis here."

Baldelli hopes to get versatile players in right field
With Cave optioned down to Triple-A, the multi-positional players on the Twins' roster -- Gonzalez and Astudillo -- will likely rotate into the outfield picture more frequently. In an early sign of that, Baldelli's lineup on Wednesday had Astudillo starting in right field for the first time in his career.

"We have guys that have played left field -- Marwin has played left field and Willians has more experience playing left field," Baldelli said. "We're going to need some of our guys to get comfortable enough to where they can go out to right field and play, and I think this is a good opportunity for Willians, not just to get some experience, but to go out there and make some plays."

Though Astudillo made several appearances in left field during Spring Training and spent the majority of his two seasons in the Venezuelan Winter League at the position, he has never started there in his Major League career. Similarly, Gonzalez has appeared in 159 games in the outfield throughout his career but has only played 7 1/3 innings in right field.