Royals catcher Salvador Perez suffered a Grade 2 MCL tear in his left knee and will miss the first four to six weeks of the season, Rustin Dodd of The Athletic reports. The injury occurred when Perez slipped while carrying luggage on Tuesday, per Jeffrey Flanagan of MLB.com. He’s unlikely to require surgery, manager Ned Yost told Flanagan and other reporters.

Perez’s accident may well lead to a career low in games played this season for the 27-year-old, who has been eminently durable throughout his Kansas City tenure. Since 2013, his first full season, Perez has appeared in no fewer than 129 games in any regular-season campaign. He logged that total last year during a season in which he hit .268/.297/.495 (103 wRC+) with a personal-best 27 home runs across 499 plate appearances. On the defensive side, Perez threw out a league-average 27 percent of would-be base stealers – a significant decline from the 48 percent he caught in 2016 – and ranked as one of Baseball Prospectus’ worst pitch framers.

Statistics aside, Perez is arguably the heart and soul of the Royals, which brings value that’s impossible to quantify. He and the re-signed Mike Moustakas are the leaders of a position player group that said goodbye to Eric Hosmer and Lorenzo Cain in free agency. Kansas City will have to make do without Perez for the first several weeks of the season, though, and that should lead to a Drew Butera–Cam Gallagher duo behind the plate (depth chart).