The 34-year-old has struggled of late -- particularly against left-handed hitting. Ohman is in the second year of a two-year contract. He appeared in 32 games and pitched in 26 2/3 innings with a 0-2 record and a 6.41 ERA.
Ohman has pitched for six teams, including the Chicago Cubs who drafted him in the eighth round of the June draft in 1998.
The White Sox will announce a corresponding move on Friday.