Now Locker has to wait and see if his season is over.
"You hope and pray that it's not and just hope for the best," Locker said.
Coach Mike Munchak noted that turnover cost the Titans at least a chance at a field goal. He said they thought Locker was shaking it off and didn't realize how hurt the quarterback was until the next play.
The Jaguars recovered and went on to win their first game this season 29-27.
"That's not CJ's fault," Locker said. "I wasn't able to get to him. I just kind of got to the point I was tired of having to come off the field because I was hurt. I wanted to give it a chance and just wasn't able to push off like I wanted to."
Locker will have more tests Monday to determine the extent of his injured foot that had him on crutches and wearing a walking boot. The Titans (4-5) host Indianapolis (6-3) on Thursday night.
"I can't imagine in four days he'd able to play as sore as he was," Munchak said of Locker.
Locker initially sprained his right hip and knee Sept. 29 against the Jets, costing him two games. He also missed five games last season with an injured non-throwing shoulder. He returned to the sideline by the start of the fourth quarter wearing street clothes.
The Titans also had rookie center
Jaguars receiver Stephen Burton also suffered a head injury announced in the fourth quarter.