Clark injured his lower left leg when he tried to make a sliding catch in the second quarter of Sunday's 31-7 loss to Atlanta. Eldridge left early in the first quarter to have X-rays on his hand. Neither returned to the game.
Coach Jim Caldwell says the Colts will have to sign another tight end this week because Jacob Tamme is the only other player they have at that spot on the active roster.
Asked if Clark's injury could be season-ending, Caldwell said he wasn't "certain."