BRADENTON, Fla. -- Pirates catcher Elias Díaz may not be ready for Opening Day as he remains sidelined due to a virus of an undisclosed nature.

Diaz has not worked out with the Pirates for the last week. Director of sports medicine Todd Tomczyk said that Diaz, Pittsburgh’s backup catcher, will be shut down or limited for a “couple of weeks” due to the illness. The Pirates are not saying for certain that Diaz will begin the season on the injured list, and Tomczyk and manager Clint Hurdle stressed they will evaluate Diaz week by week. But it seems unlikely that he will have time to get ready for Opening Day if he is out for much longer.

Whenever Diaz returns, he will have to get back in game shape and take part in a modified Spring Training program. The Pirates will begin their season in Cincinnati one month from Thursday.

Diaz reported to camp on time and in good shape. He informed the Pirates’ medical staff of his symptoms last week and sat out of the club’s workout on Feb. 20. Team doctors discovered Diaz’s virus shortly afterward. Tomczyk did not reveal details of the illness. Diaz is being treated and evaluated by the club's medical staff in Florida.

Diaz is coming off his best season in the Majors. He hit .286/.339/.452 with 10 homers, 34 RBIs and 1.6 Wins Above Replacement in 82 games last season, backing up catcher Francisco Cervelli and playing every day when Cervelli was injured. Thanks to Cervelli’s offensive resurgence and Diaz’s breakout year, Pirates catchers led the Majors last season with 5.3 WAR, according to FanGraphs.

If Diaz is not ready for Opening Day, the Pirates will likely carry Jacob Stallings as Cervelli’s backup. The Pirates would otherwise face a difficult decision with Stallings at the end of Spring Training, as the 29-year-old backstop is out of Minor League options. Stallings can’t be sent to Triple-A Indianapolis without being run through waivers, a process in which any team could claim him.

Stallings has hit .288 with a .667 OPS in 24 Major League games. Pitchers rave about his work behind the plate, and the Pirates put together a 3.56 ERA in the 91 innings Stallings caught last season.

“Stallings is here for a reason,” Hurdle said.

The Pirates do not have much Major League-ready depth behind their top three catchers, so they brought in Steven Baron as a non-roster invitee this spring to help fill that need. Baron, 28, comes with a reputation as a good defender, which he supported by making a diving catch into the Twins’ dugout on Tuesday afternoon.

“It’s definitely been something I put as a priority. I think it’s allowed me to stay around a bit longer,” Baron said. “It’s something I take pride in. I feel like if I can always do that well, I think it’ll serve me well.”

Trainer’s room

• Right fielder Gregory Polanco, working his way back from September shoulder surgery, played catch from 110-115 feet on Wednesday, Tomczyk said. Polanco also began sliding drills within the last week. He is not expected to be ready for Opening Day, but he could get at-bats in Grapefruit League games before the Pirates break camp.

Polanco is hitting without restrictions, but the Pirates are progressing with caution through his throwing program.

“He’s where he needs to be in this rehab process right now. Notably, he’s working his tail off,” Tomczyk said. “Frustrated, I’m sure, that he’s not out there playing with his buddies [Starling] Marte and Corey [Dickerson] and the rest of the gang. But I see him using this as a motivating factor.”

• Tomczyk said there have been “no hiccups” for Chris Archer and Joe Musgrove as they work their way back from offseason abdominal surgeries. Archer threw live batting practice on Sunday and Musgrove did so on Tuesday.

• Right-handers Chad Kuhl and Edgar Santana, who will miss this season after undergoing Tommy John surgery, are playing catch from 75 feet.

• Dickerson, Adam Frazier and Nick Franklin are among the players being eased into game activity this spring, but they are not limited in their pregame or back-field work. Dickerson could get into a game as soon as Thursday.

Game report

The Pirates lost to the Blue Jays, 2-1, on Thursday at LECOM Park. Right-hander Clay Holmes struck out the first two batters he faced then worked around a hit and a walk to escape the first inning. He tired in the second inning, hitting his pitch count limit with one out after giving up a single and a walk.

Holmes was happy with his performance in the first inning, especially after adjusting his pregame routine so that it will work for him as a starter or reliever.

“I’m a guy that can do both, so I think I need to be prepared for both. That’s something that I think I could have done better last year, so that’s something I’m working on,” Holmes said. “Just trying to make that consistent so, whether I’m starting or coming out of the ‘pen, I’ve got the same work in and I’m more comfortable coming into the game either way.”

Outfielder Jason Martin hit his second Grapefruit League homer in the first inning. Right-hander Luis Escobar allowed a run in the third, and Kyle Crick gave up another run in the fifth, when a two-out walk set up a Kendrys Morales RBI double.

Up next

The Pirates will travel to Tampa, Fla., on Thursday for a 1:05 p.m. ET game against the Yankees at Steinbrenner Field. Left-hander Steven Brault will make his second Grapefruit League start against former Pirates lefty J.A. Happ. Left-handers Brandon Waddell and Elvis Escobar and right-handers Alex McRae and Geoff Hartlieb are also expected to pitch for the Bucs.

The game will air exclusively as a webcast on pirates.com.