No announcement has been made by the team and the deadline to make decisions on fifth-year options is Saturday.
Had the team picked up the option, Locker would have made $14.6 million in base salary for 2015.
Locker was the eighth overall pick of the 2011 NFL draft and is set to make $2.091 million this season. Locker hasn't been able to stay healthy in his three NFL seasons and is recovering from surgery on his foot that ended his 2013 season in November.
Locker has an 8-10 record in his career as a starter. He threw for 1,256 yards with eight touchdowns and four interceptions in seven games last season.
The Titans, who have the 11th pick in the first round of next week's draft, might be in the market for a quarterback in the draft. According to the report, the team has looked at or worked out at least four quarterbacks, including Derek Carr of Fresno State, Georgia's Aaron Murray, LSU's Zach Mettenberger and Eastern Illinois' Jimmy Garoppolo.BANKS: Team-by-team previews for 2014 NFL draft