The White Sox acquired Gilbert from the Phillies on Wednesday in exchange for Aaron Combs.
Gilbert had been designated for assignment but will now join a new 40-man roster. The left-hander holds a career 4.23 ERA and 68:30 K:BB over 100 innings covering parts of four major-league seasons. Gilbert has experience as a starter and reliever and it's not clear what role the White Sox have planned for him.