The White Sox released Haase on Thursday, Scott Merkin of MLB.com reports.
Haase inked a minor-league deal in July and collected a 1.027 OPS in seven games with Triple-A Charlotte, so he might have exercised an opt-out clause. The veteran catcher slashed .162/.235/.365 in 29 games with the Giants earlier this season, and it wouldn't be a surprise to see him wind up back in San Francisco, considering the Giants' injury problems at catcher.