Oakland A’s top catching prospect Sean Murphy could miss the rest of the season after he suffered a break of the hook of the hamate bone in his right hand on Friday.

The injury was originally believed to be to Murphy’s pinkie, but further tests revealed the break in the hamate. Murphy has now broken the hamate bones in both of his hand; he injured the one in his left hand on a hit by pitch during his junior year at Wright State. That injury cost Murphy about six weeks, although Murphy wasn’t at full strength at the plate when he returned.

The bad news for Murphy is that the injury comes just as he was named to the US team for the MLB All-Star Futures Game, which he will now miss. It will also likely cost him the opportunity to log significant time in Triple-A the second half of this season.

The good news for Murphy is that this is the last time he will have to deal with a broken hamate because he doesn’t have a third one to break (the hook is removed from the hand once it is fractured). Murphy made a full recovery from the left hamate break and should have an easier time recovering his swing after this injury since it is to his top hand on the bat.

Murphy took a significant step forward in his development this season, batting .291/.359/.506 while continuing to play well above-average defense for the Double-A Midland RockHounds. He was named a Texas League mid-season All-Star and he won the league’s Home Run Derby. Ultimately, the injury shouldn’t alter his timetable to the big leagues too significantly. Given his defensive abilities, he is still likely to make his debut sometime in 2019.

To replace Murphy as the Midland primary catcher, the A’s have promoted switch-hitting catcher Jonah Heim from High-A Stockton. Heim, acquired this offseason from Tampa Bay in exchange for Joey Wendle, is having a breakout year in his first season with the A’s. A mid-season California League All-Star, Heim hit .292/.353/.433 in 80 games for the Ports. This will be Heim’s first taste of Double-A baseball.

The A’s moved Santiago Chavez from Midland to Stockton, where he will share catching duties with Collin Theroux. In other injury news, the A’s place Stockton starter Dustin Hurlbutt on the disabled list with a leg injury and moved starter Kyle Friedrichs from Midland to Stockton to take Hurlbutt’s rotation spot.