Bush threw 29 pitches on Sunday, and manager Jeff Banister said he was "unavailable" during Tuesday's 6-5 loss to the Angels. Bush has made three appearances this season, and he has posted a 4.91 ERA.
Texas is planning on Bush rejoining the team in Seattle, but this is another setback for a bullpen that has a 7.71 ERA after seven games. Bush had an outstanding rookie season for the Rangers as their right-handed setup reliever in 2016, going 7-2 with 2.48 ERA and a 0.94 WHIP.
Bush is also considered one of the club's alternatives at closer if Sam Dyson continues to struggle. Dyson has made four appearances and allowed 11 runs in three innings, with two blown saves. Tony Barnette, who was a closer in Japan, and Jeremy Jeffress, who did the job with Milwaukee before Texas acquired him last season, are the other alternatives.
T.R. Sullivan has covered the Rangers since 1989, and for MLB.com since 2006. Follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.