The Achilles' injury Colts quarterback Daniel Jones sustained in the first quarter of Sunday's Week 14 loss to the Jacksonville Jaguars is "not looking good," head coach Shane Steichen said, adding it could cause Jones to miss the remainder of the 2025 season.

"I don't have the full details on it," Steichen said. "We'll get more clarity on that."

On a third-and-eight dropback, Jones threw a pass and fell to the ground, clutching between his calf and ankle on his right leg. He tried to get up and walk to the sideline, but couldn't make it more than a few steps. When trainers raced to him, he slammed his helmet on the turf twice in frustration.

Jones was quickly ruled out of the game with an Achilles' injury. He returned to the Colts' sideline in the second half with a boot on his right foot.

With Jones out, rookie backup Riley Leonard stepped in for the final three quarters of Sunday's game, which was the first extended action he's seen in his NFL career. Leonard, a 2025 sixth-round pick from Notre Dame, completed 18 of 29 passes for 145 yards with an interception, a rushing touchdown and a passer rating of 60.3.

Anthony Richardson, who the Colts penciled in to back up Jones after a training camp competition, remains on injured reserve due to a fractured orbital bone he sustained in a freak pregame accident in Week 6. Steichen said last week Richardson continues to rest his eye while awaiting clearance to return to practice.