The surging Kansas City Royals were dealt a blow on Sunday when they placed catcher Salvador Perez on the seven-day concussion disabled list.
The Royals' medical staff labeled the injury a low-grade concussion, but it is unknown how long Perez might be sidelined.
The 23-year-old Perez is hitting .278 with four home runs and 43 RBI this season.
His backup is George Kottaras, who started Sunday's game against the New York Mets and is expected to get the bulk of playing time behind the plate until Perez returns.
The Royals are 12-3 since the All-Star break and moving into American League Wild-card contention.