Firkser was set to become an exclusive-rights free agent in March after leading the Titans in postseason touchdown receptions with two. Terms of the deal were not released.
The New York Jets signed Firkser as an undrafted free agent out of Harvard in 2017 before waiving him that year. He landed on the Kansas City Chiefs' practice squad as a rookie and was waived in April 2018. The Titans picked Firkser up a month later.
Firkser began the 2018 season on the Titans' practice squad but was signed to the active roster and finished with 19 receptions for 225 yards and a touchdown. He followed up with 14 catches for 204 yards and a score in 2019. Firkser's two career regular-season touchdowns came against the Jets and Chiefs, the two teams that waived him.
Firkser came on as a favorite target of quarterback Ryan Tannehill in 2019. Firkser caught three out of five targets from Tannehill for 45 yards and two touchdowns in the playoffs, becoming the first player from Harvard to score a touchdown in the postseason.