The five-player swap also included the Red Sox receiving Tyler Samaniego, a lefthanded minor league reliever, and minor league catcher Adonys Guzman. They also sent righthanded pitching prospect Jesus Travieso to the Pirates.

Oviedo, a Cuban righthander who will be 28 next season, was the biggest name involved.

He missed all of 2024 because of Tommy John surgery and much of 2025 because of a right lat injury. But the Red Sox were encouraged, a source said, by how Oviedo performed upon returning: 3.57 ERA in nine starts across August and September, with a career-best 25 percent strikeout rate (and career-worst 13.5 percent walk rate). His fastball velocity, at 95.5 miles per hour on average, held compared to his pre-surgery marks.

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Across parts of five seasons in the majors, the 6-foot-6-inch, 275-pound Oviedo owns a 4.24 ERA and 1.38 WHIP, collecting fewer than two strikeouts for every walk along the way. He has experience in the bullpen but the Sox intend to stretch him out as a starter, a source said.

Oviedo has two years of team control remaining — so he wouldn’t become a free agent until after 2027 at the earliest — and can be optioned to the minors.

Oviedo doesn’t neatly fit into chief baseball officer Craig Breslow’s stated pitching approach this offseason — not spending much time on spot Nos. 3-10, he said — but offers additional insurance for the uncertain back end.

The Red Sox’ top three in the rotation at the moment are Garrett Crochet, Sonny Gray, and Brayan Bello. Among those who also are in the picture: Patrick Sandoval and Kutter Crawford are coming off missed seasons because of injuries, and Hunter Dobbins, Payton Tolle, and Connelly Early have minimal experience in the majors. Kyle Harrison and others are in that conversation, too.

Garcia had been the Red Sox’ No. 6 prospect, according to Baseball America’s latest rankings, while Travieso was No. 16.

The Red Sox traded outfield prospect Jhostynxon Garcia to the Pirates on Thursday as part of a five-man deal.Danielle Parhizkaran/Globe Staff

Garcia, who turns 23 next week, hit very well in the upper minors in 2025, helping him earn a five-game cameo in the majors. But with the Red Sox outfield overcrowded as it is — with Roman Anthony, Ceddanne Rafaela, Wilyer Abreu, and Jarren Duran on the roster — he didn’t have a clear path to a regular spot.

Travieso, who pitched stateside for the first time last season, is essentially a pitching lottery ticket, as an 18-year-old who reached triple digits with his fastball. He is more likely to be a reliever long-term.

Of the pair of lower-profile players the Sox received, Samaniego is closer to the majors, having pitched at Double A (4.20 ERA) in parts of the past four years. He will be 27 next season.

To clear a spot on the 40-man roster for Samaniego, the Red Sox designated Cooper Criswell for assignment.

Guzman is the third minor league catcher acquired by the Red Sox in the past three weeks. Born in the Bronx, he played at Boston College in 2023, then transferred to Arizona for two years. The Pirates drafted him in the fifth round last July.

Tim Healey can be reached at timothy.healey@globe.com. Follow him @timbhealey.