Welington Castillo begins a rehab assignment with Triple-A Charlotte on Friday. The White Sox catcher is in the lineup as the designated hitter against Louisville, batting second.
Castillo, who was suspended 80 games after a positive test for Erythropoietin (EPO), a performance-enhancing substance, is eligible to rejoin the Sox on Thursday in Detroit.
The Sox have gotten good play behind the plate since he was suspended in May. The combination of Omar Narvaez and Kevan Smith has helped the Sox produce a .