Foster (back) elected free agency Monday.

Foster was placed on the 15-day injured list Friday with a lower-back disc herniation.

The White Sox recalled Foster from Triple-A Charlotte on Tuesday, LaMond Pope of the Chicago Tribune reports.

Foster was added to the White Sox's roster as the 27th man ahead of the second game of Wednesday's doubleheader against Texas.

Foster was optioned to Triple-A Charlotte on Monday.

The White Sox reinstated Foster (elbow) from the 60-day injured list Friday.

Foster (elbow/back) is expected to resume his rehab assignment with Triple-A Charlotte in the coming days, Daryl Van Schouwen of the Chicago Sun-Times reports.

Foster's (elbow) rehab assignment with Triple-A Charlotte has been paused due to a strained back, Vinnie Duber of AllCHGO.com reports.

Foster's (elbow) rehab assignment was transferred to Triple-A Charlotte on Friday, Scott Merkin of MLB.com reports.

Foster (elbow) began a rehab assignment Monday in the rookie-level Arizona Complex League, striking out two over a scoreless inning.