Hasselbeck started five game last season when starter Jake Locker suffered a shoulder injury, finishing with 1,367 passing yards, seven touchdowns and five interceptions in eight games overall.
The 37-year-old started all 16 games for the Titans in 2011.
"I want to thank Matt for his contributions to our team over the last two years," Webster said. "He was an important part of the transition process -- he was a pro at every turn and he provided an example to the rest of the team."
Over his 14-year NFL, Hasselbeck has thrown for 34,517 yards with 201 touchdowns and 147 interceptions.