The former first-round pick was injured in the second quarter on an option play. "I don't know exactly how it happened, but when I got up from that run, I could feel it," he said.
Locker tried to run one more play after the hit, but he couldn't put weight on his foot and he ended up fumbling an attempted handoff to Chris Johnson. When Locker left, the Titans trailed 13-0. By the time it was over, Jacksonville eked out a 29-27 win.
Going forward, veteran backup Ryan Fitzpatrick will almost certainly be the starter, and Locker will head into 2014 with questions about whether he truly is the team's franchise quarterback.
But unlike the previous two years, Locker played well in seven appearance this season. According to FootballOutsiders.com, he ranked 21st in QB efficiency, which doesn't sound particularly impressive until you realize that he was 31st in 2012. Looking at more conventional stats, Locker's completion percentage has increased from 51.5 as a rookie to 56.4 last season to 60.7 this season.
Locker's future in Tennessee could depend in large part on whether the coaching staff returns. If they're out -- and losing to the 0-8 Jags isn't exactly the best way to stay in ownership's good graces -- then it's reasonable to think that a new coach will want a new franchise quarterback.
For now, the Titans will try to regroup following Sunday's debacle, and remain in the AFC South race. At 4-5, Tennessee is currently in second place in the division, two games behind Indianapolis.