OAKLAND -- Be careful when cleaning your cleats. You might miss the first two months of the season.

Back in Spring Training, A’s ace Paul Blackburn was scraping some dirt off his cleats when his hand slipped and he cracked a fingernail. As he tried to rehab, the 29-year-old right-hander developed a blister that pushed back his progress. Blackburn also spent time on the paternity list, as his wife welcomed their second child into the world on May 5.

Now, Blackburn is finally set to make his season debut on Monday against the Braves, A’s manager Mark Kostay announced. The 2022 All-Star rejoined the team on Friday in Oakland and spoke to reporters about how frustrating it has been to be unavailable this season.

“It’s just kind of freakish. It sucks,” Blackburn said. “I’ve missed 52 games, whatever it is now. It’s frustrating, very frustrating. It could always be worse. It could have been something a lot bigger injury-wise. Thankfully it’s just a fingernail and a blister, but for it to keep me out until the end of May, it’s very frustrating.”

Blackburn made three rehab starts for Triple-A Las Vegas this month. In his latest on Wednesday, he allowed one run over five innings, striking out five while walking one on 73 pitches. Blackburn said he has no physical limitations or tweaks to his grip or delivery with the injury, adding that he got through a 25-pitch bullpen session without issue Friday.

The A’s could use the help in their rotation these days. Entering play Friday, Oakland ranked last in MLB with a 6.88 team ERA and 7.14 ERA from its starters. Last season, Blackburn represented the A’s at the Midsummer Classic, but he then made just three starts in the second half before getting shut down with a tear of the flexor tendon sheath in his pitching hand.

“Last year was great,” Blackburn said. “But I’m not coming out here and trying to do what I did last year. That’s last year. There’s things I learned about myself and about this game last year that I’m going to bring into this game, but I’m not going to try and chase that ghost from last year.”

At the moment, the A’s rotation includes young players like JP Sears, Luis Medina, Hogan Harris -- all of whom are trying to learn how to be big league pitchers on the fly. Blackburn returns as the longest-tenured pitcher on the staff, and he knows that he has to be something of a mentor in the clubhouse.

“Being the older guy, it’s kind of my job to do that with younger guys,” Blackburn said. “At the end of the year -- whatever our record is, is our record. But I hope everyone just kind of takes a step back and says, ‘You know what? I got better this year.’”