Charlie Whitehurst has replaced Locker for the Titans, who owned a 5-3 lead when the injury occurred.
The Titans' emergency third quarterback is receiver Kendall Wright, who is inactive for a second game in a row with a broken bone in his hand.
Titans starter Zach Mettenberger was knocked out of each of the Titans' last two games. He suffered a right shoulder sprain in Houston on Nov. 30. A week later he injured it worse against the Giants.
Mettenberger is reportedly done for the season, although the Titans have not put him in injured reserve.