Morales has bounced between the rotation and bullpen this season, going 3-2 with a 3.14 ERA overall. In six starts, he owns a 3.06 ERA and 35-to-11 strikeout-to-walk ratio.
His most recent effort came as a fill-in for the injured Josh Beckett. Morales lasted six innings for the victory, holding the Twins to one run on three hits while throwing 106 pitches.
"I needed to throw my pitches," Morales said. "I felt great concentration. I know the team needed to win. I tried to do what I need to do, get the hitters out and do my thing."
Valentine then elected to have Morales remain in that role even after Beckett's return, while skipping Aaron Cook in the rotation. That leaves Morales to make his first career start against the Indians, who have split the first two games of the series with the Red Sox.
Boston's win on Friday night snapped a three-game losing streak, although the club still has dropped seven of 10. Cleveland is mired in a worse stretch, having lost 12 of 14.
The Indians will counter Morales with Zach McAllister. The rookie right-hander's last outing, on Monday against Minnesota, was the shortest of his career, at 1 2/3 innings. He also gave up a season-high nine runs, although only two were earned.
McAllister retired the Twins in order in the first inning, but a two-out error in the second was followed by seven unearned runs and McAllister's exit. That left him winless in his last four starts.
"Once the hits started coming, they didn't stop," he said. "It was one of those where you just wanted to stop the bleeding, and I wasn't able to do that."
Red Sox: Podsednik back in the outfield
On Friday, Boston's new outfielder was the same as its old outfielder.
Scott Podsednik started in left and went 1-for-3 against the Indians, less than two weeks after the Red Sox traded him to the D-backs. Soon after joining Arizona, the 36-year-old refused a demotion to Triple-A, cleared waivers and became a free agent.
The Red Sox called, and now Podsednik is back to serve as a fourth outfielder. Ryan Kalish was optioned to Triple-A Pawtucket to make room for Podsednik, who hit .387 in 19 games for Boston earlier this season.
"We felt like it was just a little upgrade over the way Ryan was performing," Valentine said. "Maybe we'll get a little upgrade, and an experienced guy who's used to not playing all the time."
Indians: Kipnis batting sore neck
Second baseman Jason Kipnis missed his second straight start on Friday due to pain in his neck. The Indians are hoping he can return on Saturday, but Kipnis is exercising caution with this particular ailment.
"I don't mind playing through injuries or pain," Kipnis said, "but the neck is something you just can't mess with. There's progress, but it's still sore."
Kipnis also is dealing with a rough patch at the plate, going 4-for-39 (.103) with one extra-base hit over his past 11 games.
During Kipnis' absence, Jason Donald has started both games at second base.
McAllister made his second start of the season at Boston on May 12. He racked up eight strikeouts but also gave up four runs in seven innings to take the loss.
Morales has tossed 1 1/3 scoreless innings over two relief appearances against the Indians this season.