The Titans believe Young has a torn medial collateral ligament in his left knee that will sideline him two to four weeks, reports NFL Network's Adam Schefter. Young is expected to undergo an MRI exam on Monday that would confirm the initial diagnosis.
Young was moving very gingerly while trying to get dressed with crutches at his locker and left without talking to reporters.
He was injured on a bootleg when Jaguars linebacker Daryl Smith collided with his left leg a couple plays after Tennessee coach Jeff Fisher had to talk to his quarterback about whether he could go back into the game. Young had thrown his helmet on the sideline after being intercepted for the second time, and he didn't have his helmet with him when the Titans got the ball back.
Backup quarterback Kerry Collins appeared to be going in, and Fisher took his headset off and talked with Young, who then pulled on his helmet and went into the game.
Fisher said the discussion only involved Young's hamstring and whether he felt physically able to return.
"Regarding the hamstring, he said, `It's tight,' and I said, `If it's tight, we'll go with Kerry and try to talk him back into it, and he felt good," Fisher said. "When he got out there, he moved. He didn't have any issues with the hamstring on the bootleg on which he was hurt."
Young's second interception came a play after the Titans had picked off one of David Garrard's passes. Trimming interceptions is a key focus for Young this season after being picked off 17 times with only nine touchdown passes in 2007.
Asked if he was disappointed with Young's attitude, Fisher said no.
"He's very competitive," Fisher said. "I've never seen him jump up and down and high-five his teammates after he throws an interception."
The Associated Press contributed to this report