Injuries to Carson Palmer and Drew Stanton allowed Gabbert to make five starts last season with the Arizona Cardinals. The 28-year-old Gabbert finished 95 of 171 for 1,086 yards with six touchdowns and six interceptions during that span, posting a 2-3 mark with one of the wins -- 12-7 on Dec. 10 -- coming at the expense of Tennessee.
A first-round draft pick (No. 10 overall) of Jacksonville in 2011, Gabbert endured three rocky seasons with the Jaguars, going 5-22 as a starter.
Gabbert resuscitated his career with the San Francisco 49ers in 2015, starting the final eight games and tossing 10 scoring passes versus seven picks while completing a personal-best 63.1 percent of his passes.
Like Mariota, Gabbert can be a threat with his legs, rushing for 440 yards in 18 games over the past three seasons.
Gabbert owns an 11-34 mark as a starter, throwing for 8,437 yards, 44 touchdowns and 43 interceptions. He also has been sacked 133 times, including 23 last season with the Cardinals.
The Titans also have quarterbacks Alex Tanney and Tyler Ferguson on the roster.