The Red Sox released Thaiss on Friday, Chris Cotillo of MassLive.com reports.
Thaiss has spent the entire season at Triple-A Worcester, where he's slashed an ugly .201/.314/.313 with three homers, 24 RBI, 17 runs scored, one stolen base and a 20:26 BB:K across 170 plate appearances. The 31-year-old will look for an opportunity elsewhere after appearing in 60 games with the White Sox and Rays last season.