Mark Appel underwent an appendectomy on Thursday.
The 22-year old right-handed pitcher, who was selected by the Astros with the first pick in the 2013 MLB June Amateur Draft, is recovering well from what the team described as a routine procedure according to a release.
The Stanford product made 12 starts for the Astros minor league system last year and is expected to be well enough to be ready when pitcher and catchers report for the start of Spring Training on Feb. 15.
The Astros also announced that left-handed pitcher Raul Vales underwent arthroscopic surgery on his left knee this week. The team expects him to be in Kissimmee, Fla. for the start of Spring Training as well, though the recovery time is expected to run four-to-six weeks.