(CBS) White Sox hitting coach Greg Walker resigned Wednesday, with the move becoming official after the team finishes its last game of the season later in the day.

Walker was not expected to return after manager Ozzie Guillen left the White Sox Monday. The hitting coach said Wednesday that he made his decision to resign earlier in the month. He revealed earlier this season that Chairman Jerry Reinsdorf had to convince him in the offseason to return in 2011 so it’s no surprise he’s leaving now.

Walker has been the hitting coach since 2003 and served in the same roll with Triple-A Charlotte in 2002 and 2003 before he was promoted. He also played with the White Sox from 1982-90.