NASHVILLE, Tenn. -- The Tennessee Titans announced Tuesday that tight end Jonnu Smith and right tackle Jack Conklin have been placed on injured reserve. Both Smith and Conklin suffered knee injuries during Tennessee's win over the Jaguars last week.

Before suffering an MCL injury, Smith posted 20 receptions for 258 yards and three touchdowns this season.

Smith had a rocky start but worked hard to make himself a preferred target for quarterback Marcus Mariota.

"You see how hard he works, how much he cares and the improvement that he makes, and how much it means to him," coach Mike Vrabel said.

Smith's injury came while he was blocking for running back Derrick Henry's record-setting 99-yard touchdown run in the second quarter. The tight end remained on the ground after Henry scored and was helped up by trainers. He walked directly into locker room with help from the trainers.

Anthony Firkser will likely replace Smith in the starting lineup.

"I'm sure his role will change," Vrabel said of Firkser. "He gets open, he catches the ball. The quarterbacks have confidence in him. We just have to continue to progress and develop him as a blocker, as an all-around tight end and not just a [substitute] tight end."

Conklin will be replaced by reserve guard/tackle Dennis Kelly. Conklin, a third-year right tackle, fought his way back from a ligament tear suffered in the Titans' divisional playoff loss to the Patriots in January.

In corresponding moves, the Titans signed free-agent offensive lineman Austin Pasztor and added tight end Cole Wick to the active roster from the 49ers' practice squad.