HOUSTON --Astrosright-hander Aaron Sanchez will have surgery on his throwing shoulder and will miss the remainder of the season.
Meanwhile, outfielder George Springer, whose head hit the outfield wall Tuesday night,has been diagnosed with a concussion and will miss a few games before returning early next week.
Sanchez hasn't pitched since Aug. 20 because of what the team said was a sore right pectoral muscle. The team had expected him to return this season, but general manager Jeff Luhnow said Thursday morning that he would have the unspecified procedure on his right shoulder next week and wouldn't return this year.
Sanchez was acquired from Toronto on July 31 and combined with three relievers to throw a no-hitter in his first start for the Astros on Aug. 3.
Springer, whose head hit the wall after he made a leaping catch of a Ryan Braun shot to deep center to end the fifth inning, was carted off the field.
He has a .297 batting average with 30 home runs and 78 RBIs this season for the AL West-leading Astros.
The Associated Press contributed to this report.