Royals All-Star catcher Salvador Perez to undergo thumb surgery

The Kansas City Royals head into Friday night's game against the Oakland Athletics sitting at 25-43 on the season and in the basement of the American League Central standings. 

Kansas City offered even more bad news for fans ahead of the final weekend of June. 

Per ESPN and the Royals' website, seven-time All-Star catcher Salvador Perez will soon undergo surgery to repair the ulnar collateral ligament in his left thumb. While Kansas City says Perez "is expected to return this season," Fox4KC notes that it's unclear how long the 32-year-old will be sidelined. 

Perez missed time this spring due to a stint on the injured list related to what was referred to at the time as a left thumb sprain. Most recently, he exited Tuesday's extra-inning win over the Los Angeles Angels in the third inning of that contest because of his thumb. 

The Royals placed Perez on the IL and reinstated Edward Olivares from that same list in a corresponding roster move. 

Perez finished last season tied for the MLB lead with 48 home runs and a league-best 121 RBI, as noted by ESPN stats. Before his setback this year, however, he was hitting just .211 with 11 home runs and 34 RBI.