Gwyn was diagnosed with a fractured fibula that will likely require surgery, Jamison Hensley of ESPN.com reports.
The fourth-year center is expected to be sidelined for 2-to-3 months, though likely more if he ends up undergoing surgery. Backup center Ethan Pocic (knee) is also expected to miss significant time, and with Danny Pinter (knee) on injured reserve, that leaves rookie first-rounder Olaivavega Ioane as the starting center for the Ravens for Week 4 against the Titans.