Jaguars coach Jack Del Rio was caught off guard on Friday morning when he was told his starting quarterback, Byron Leftwich, was favoring a sore left ankle.
"He didn't practice today. He'll get an MRI this afternoon. He came in today and it was swollen and sore," Del Rio said following Friday's practice.
Leftwich was added to the Jaguars injury report as "questionable" for Sunday's game in Houston. The injury is thought to have occurred in Thursday's practice, though it did not present itself at that time. Leftwich fractured his left ankle in week 12 of last season and missed the remainder of the regular season.
Meanwhile, defensive tackle Marcus Stroud (ankle), wide receiver Matt Jones (hamstring) and reserve offensive lineman Stockar McDougle (ankle) have been ruled "out" for Sunday's game. They had previously been listed as "doubtful."
"We'll see what the MRI results say and make a decision leading up to the game," Del Rio said of Leftwich. "He practiced (Thursday) and walked out of here. He just woke up this morning sore. We hope it'll settle down and be OK."
David Garrard took Leftwich's place with the first-team offense in practice on Friday. Garrard threw for 292 yards and a touchdown in leading the Jaguars to a 38-20 win in Houston late last season. Garrard had replaced Leftwich following the latter's ankle injury in Arizona.
"As a team, we prepare David and Quinn (Gray) and learn from the (MRI) results how to respond," Del Rio said. "I don't want to downplay it. Any time a player misses time, it's a concern. Anytime your quarterback misses time, it's more concern.
"I was given the news at 10 o'clock this morning. Prior to 10 o'clock this morning, I was under the assumption my starting quarterback would practice today and play well on Sunday," Del Rio added.