PITTSBURGH -- Pirates third-base prospect Ke'Bryan Hayes has tested positive for COVID-19, manager Derek Shelton confirmed.

Hayes has not been able to participate at all in the Pirates’ Summer Camp workouts at PNC Park. His absence remained unexplained until he gave the team permission to share news of his positive test, which Shelton announced after Pittsburgh’s workout on Sunday at PNC Park. Hayes will need to receive two negative tests at least 24 hours apart before he’ll be able to rejoin the team.

Shelton acknowledged that it’s difficult for the Pirates to lose this much crucial development time with Hayes, their No. 2 prospect who appeared to be on the verge of reaching the Majors when Spring Training was shut down.

“As we’ve talked about numerous times, not just for Key but for all of our prospects, this is a big year for us,” Shelton said. “We have to be very thoughtful of how much work we get them and try to get them as much work as possible. Anytime we lose prospect time, it’s challenging. But it’s just something that we’ll adapt and adjust and move forward with.”

Hayes, MLB Pipeline’s No. 41 overall prospect, was invited back to big league camp after being optioned to Triple-A on March 20. After taking a step forward at the plate in 2018, the 23-year-old hit .265/.336/.415 with 10 homers in 110 games for Triple-A Indianapolis last year. A defensive standout at third base, Hayes has worked well with hitting coach Rick Eckstein during spring camp the past two years -- which could bode well for his future in Pittsburgh.

Hayes may not have cracked the Opening Day roster even if he had been able to take part in Summer Camp, as Colin Moran is expected to be the Pirates’ regular third baseman to start the season. But there was hope that Pittsburgh would see a lot of Hayes at some point this season, setting him up as the third baseman of the future. Now, his timeline is in question as he remains in quarantine.

Hayes is the fourth Pirates player to have a confirmed positive COVID-19 test since players returned to Pittsburgh. Reliever Blake Cederlind and outfielder Socrates Brito tested positive early in camp, though Brito has since returned to the field. Right fielder Gregory Polanco’s positive test was announced on Friday.

Closer Keone Kela has not been active during Pirates camp, and he was placed on the injured list Thursday. The reason for Kela’s absence remains undisclosed.

Around the horn
• During the AT&T SportsNet Pittsburgh telecast of Saturday’s exhibition, right-hander Trevor Williams said he will start the Pirates’ second game of the season in St. Louis after pitching in Monday’s exhibition game in Cleveland. Shelton confirmed that announcement on Sunday but didn’t reveal Pittsburgh’s rotation plans beyond Opening Day starter Joe Musgrove and Williams.

“When I told him today that I was going to say that to you [reporters], he was like, ‘OK, I think that may be already out,’” Shelton said, laughing.

• Shortstop Cole Tucker, who began working in the outfield on Friday, will play in either center or right field during Monday’s exhibition in Cleveland, Shelton said. During Sunday’s simulated game featuring relievers Clay Holmes and Nik Turley, Tucker stood in center field alongside first-base coach Tarrik Brock, who works with the club’s outfielders.

“What an athlete he is. Just watching him move around the outfield, he’s going to be great out there,” bench coach Don Kelly said. “Just reiterating, like, shortstop is your position; you’re not going to lose that. You have to focus on maintaining that. But it will help him and help the team to be able to be more versatile. There’s no doubt in my mind that he can play outfield.”

• Shortstop Kevin Newman, who was held out of Saturday’s game as Shelton declared him “a little dinged up,” went through a full workout on Sunday afternoon at PNC Park. The shortstop performed agility drills under the watch of director of sports medicine Todd Tomczyk, played catch, ran drills at shortstop then hit and ran the bases during Sunday's simulated game.

• Polanco shared videos of himself working out on his Instagram account on Saturday. Polanco, who is sidelined after testing positive for COVID-19, posted short clips in which he was working out indoors using resistance bands. On Saturday’s telecast, general manager Ben Cherington said Polanco is asymptomatic and “feeling great. … No issues at all. He’s just going to have to be patient and get through the protocol, and he’ll be back before we know it.”

• Pirates broadcaster Greg Brown revealed during Saturday’s telecast that color analyst Bob Walk is recovering from COVID-19. Walk is awaiting more negative tests before rejoining the Bucs’ booth.