PITTSBURGH -- From the time the Pirates introduced their piggyback plan to Steven Brault and Chad Kuhl, they advised the two pitchers to stay flexible because their jobs might change. After two turns through the rotation, their roles are being flipped for at least one outing.

Brault made two starts to begin the season, with Kuhl coming on in relief in both games, but it will be Kuhl who gets the start Friday night against the Tigers at PNC Park. Manager Derek Shelton declined to say whether Brault will follow Kuhl on the mound, but it seems likely considering Kuhl is only stretched out to pitch a maximum of four innings.

The switch came as a surprise not only because Brault looked excellent in his first two turns as the front half of the tandem-starter duo, most recently working three perfect innings Sunday at Wrigley Field, but also because the Pirates initially listed Brault as their probable starter for the series opener. Shelton announced Thursday morning that Kuhl would start, calling the prior listing “a miscommunication.”

The players involved were apparently aware, however. Kuhl said Shelton and pitching coach Oscar Marin have been informing them of the plan after their between-outings bullpen sessions.

“I think we kept that open mindset where we knew that it could go back and forth,” Kuhl said. “They were very transparent about letting us know ahead of time and letting us know that it could be either one of us, and it’s not just a set thing. They were very transparent and open about that.”

Kuhl exited his last outing Sunday at Wrigley Field early due to an abrasion to the cuticle of his right index finger, and Shelton said earlier this week that Kuhl’s finger felt “tender” the day after he resumed throwing. Kuhl said the injury occurred when his fingernail tore into his cuticle on his final warmup pitch before his second inning of work. His finger began bleeding, and he couldn’t put pressure on the ball to throw his fastball.

But Kuhl said he was able to throw a bullpen session on schedule. More than anything, the injury was a frustrating interruption because he felt as good as ever on the mound in his previous inning.

“Just because it’s so small and you know that it kind of popped up out of nowhere,” Kuhl said. “I tore my elbow and got two more outs in New York and I couldn’t muscle through this, so it’s a little bit of a frustrating thing. But we’ll get through it.”

Friday will be Kuhl’s first regular-season start since that night at Citi Field on June 26, 2018, his final outing before undergoing Tommy John surgery later that year. Part of the reason the Pirates put him and Brault in this piggyback setup was to protect their health as they return from injuries, but as they get built up to pitch deeper into games -- and as Pittsburgh’s pitching injuries pile up -- they could be split up to fill two spots in the rotation.

“I think there’s a point where we could talk about that when they get lengthened out,” Shelton said. “It’s probably a conversation that Oscar and I will continue to have. So to say that’s going to happen, I’m not saying that. But there’s a chance that could happen.”

"I think we'll kind of see how things progress and move forward, but we haven't really discussed anything like that,” Brault added. “I think maybe after this next start, we'll see kind of where things go after that. But for now, it's just kind of business as usual."

Around the horn
• The Pirates optioned two hitters, José Osuna and Guillermo Heredia, to their alternate training site on Wednesday night in advance of Thursday’s deadline to trim rosters to 28 players. Shelton said Thursday the moves were about the “need to preserve as much pitching as possible” in light of all their recent injuries.

“Difficult decision on both of ‘em because of who they are as people,” Shelton said. “Just felt, right now, it was the best situation for us."

• The versatility of players like Erik González, Cole Tucker, Phillip Evans and JT Riddle also allowed the Pirates to send down Osuna, a corner infielder/outfielder, and Heredia, an extra outfielder. Tucker seemingly surpassed Heredia on the outfield depth chart, playing both center and right field, and he remains an option at shortstop. Evans has started eight games at third base, freeing up Colin Moran to play first base when Josh Bell is the designated hitter.

• Riddle, activated from the injured list on Wednesday, made his first start for the Pirates on Thursday at shortstop, batting seventh. Kevin Newman will start at shortstop on Friday against Tigers lefty Matthew Boyd, Shelton said.