Apostel has appeared in three games for Triple-A Round Rock since returning from a knee injury, going 3-for-12 with a solo home run, a double and a walk in those contests.

Apostel (knee) was outrighted to Triple-A Round Rock on Thursday, Kennedi Landry of MLB.com reports.

Apostel will miss the remainder of the season after undergoing surgery to address an issue with his knee cartilage, independent baseball journalist Jeff Wilson reports.

Apostel was promoted to Triple-A Round Rock from Double-A Frisco on Monday.

Apostel (undisclosed) has gone 1-for-11 over three games with Double-A Frisco since the affiliate reinstated him from its 7-day injured list July 28.

Apostel, who was placed on Double-A Frisco's 7-day injured list July 6 with an unspecified injury, began a rehab assignment with the Rangers' rookie-level Arizona Complex League affiliate last week. Through four ACL games, Apostel has gone 5-for-12 with three home runs, three walks, six runs and eight RBI.

Double-A Frisco placed Apostel on the 7-day injured list Tuesday with an unspecified injury.

Apostel will start the season at Double-A Frisco, Sam Blum of the Dallas Morning News reports.

Apostel was optioned to Triple-A Round Rock on Friday, Jeff Wilson of the Fort Worth Star-Telegram reports.

Apostel (back) has made three appearances for the Rangers in Cactus League play, going 1-for-3 at the plate across those contests.