The White Sox informed Thaiss on Monday that he'll be included on the Opening Day roster, Scott Merkin of MLB.com reports.
Thaiss will likely open the season as the No. 2 catcher behind incumbent Korey Lee after posting an .892 OPS across 12 Cactus League games. Thaiss and Lee may not be ticketed for season-long stays on the active roster, however, as catching prospects Kyle Teel and Edgar Quero will open the campaign at Triple-A Charlotte but should be ready to make their MLB debuts at some point later in 2025.