Kelce suffered a hyperextended knee at Tuesday's practice, Pete Sweeney of ArrowheadPride.com reports.
Kelce's injury comes just days before Thursday's regular-season opener against the Lions and clouds his status for the contest. Coach Andy Reid called Kelce uncertain for Thursday's game, but he said Kansas City's training staff would continue to monitor his health, per Nate Taylor of The Athletic. Noah Gray would likely step up as the team's top tight end if Kelce were to miss any time, but there's no easy replacement for Patrick Mahomes' favorite target. Top wideouts Kadarius Toney (knee), Marquez Valdes-Scantling and Skyy Moore would likely see bumps in target share if Kelce can't go.