FORT MYERS, FLA. – Six days after Justin Topa had a spring training outing interrupted by shoulder tightness, he was back pitching in a bullpen session Tuesday.

It was probably the best-case scenario for Topa, who was limited to three relief appearances last season because of a knee injury and arm fatigue. He felt tightness in his shoulder after releasing pitches when he tried to extend his arm at the end of his delivery.

"It was more precautionary than anything," Topa said. "I was joking, fortunately or unfortunately, I know what elbow injuries feel like. I've never had any shoulder stuff."

Topa exited after seven pitches March 5, inducing a flyout before giving up a homer. The tightness appeared, Topa said, after his third pitch. The velocity on his final pitch, a slider, was down 2 mph compared to one he threw earlier in the inning.

"I was like, OK, maybe a 'it's not loose' type situation," Topa said. "I threw a couple more, and it was still there. At that point, it was like, all right, I'm feeling it pretty much every pitch. Let's get out of here and take a look at it."

After Topa rested his shoulder for a day, he didn't feel any tightness when he ramped up again. He didn't require an MRI exam, because his shoulder maintained normal strength and range of motion.

After playing catch for three days, working up to 90 feet, he pitched in a bullpen session Tuesday, and he expects to throw again Friday. He's not sure why the tightness flared up, but he said, "Thankfully, it was a pretty quick down time."

Matthews delivers camp's 'sharpest outing'

Zebby Matthews, in his first outing since he left a game with hip discomfort, struck out five batters across three scoreless innings during the Twins' 6-5 walk-off loss to the Boston Red Sox on Wednesday at JetBlue Park.

With a fastball regularly touching 97 mph, Matthews has permitted four hits and one walk in 9⅓ scoreless innings with 12 strikeouts.

"He probably had the sharpest outing that we've seen all spring," Twins manager Rocco Baldelli said. "He looked fantastic. He threw some pitches I didn't even know what they were. I think he threw a 94-mph cutter, which I didn't even know he did."

Twins pitchers totaled 16 strikeouts, but the Red Sox strung three of their six hits in the ninth inning. Mark Kolozsvary hit a game-winning RBI single off minor leaguer Cody Laweryson.

After the Twins scored three runs in the top of the first inning, it took Joe Ryan a few batters to find his rhythm.

Ryan, who threw 54 pitches in 2⅓ innings, allowed a three-run homer to Triston Casas in the first inning, then retired the next seven batters with five strikeouts.

"That's my one gripe with the pitch clock," Ryan said. "How long was that inning, 30-40 minutes? Then I get a minute and 30 seconds to run out there, play catch and get ready to go. I just don't think that's smart. I feel like if it takes 30 minutes, you should get an extra minute to throw if you need it."

Carlos Correa and Matt Wallner recorded two hits each while Royce Lewis, Willi Castro and Ryan Jeffers provided RBI singles.

Culpepper scratched from showcase

Kaelen Culpepper, the Twins' first-round pick from last summer's amateur draft, was scratched from Saturday's prospect showcase roster because of a hamstring injury.

Culpepper, a 22-year-old shortstop, took ground balls at the Twins' facility, and his injury isn't expected to affect his availability for the start of the minor league season. Culpepper finished last year at Class A Cedar Rapids.

The Twins will send a group of prospects to face the Toronto Blue Jays' prospects Saturday, which will be streamed on the MLB app. The Twins have only two of their top 10 prospects in MLB Pipeline's rankings scheduled to participate in the showcase: second baseman Luke Keaschall, who remains in big-league camp, and shortstop/outfielder Brandon Winokur.

Eeles to miss start of season

Payton Eeles underwent a minor knee procedure during the offseason, addressing a cartilage issue, and he will begin the season on the Class AAA injured list. The Twins are hopeful it won't be a prolonged absence as he recovers from surgery.

Eeles, 25, was one of the biggest surprise stories in the minor leagues last year. The 5-5 second baseman signed with the Twins for $500 out of an independent league, then stormed from low-A to the St. Paul Saints. In 64 games at Class AAA, he batted .299 with eight homers, 11 doubles and 30 RBI while posting a .419 on-base percentage, putting himself on the radar for a big-league promotion this year.