Sources told ESPN and NFL Network that Walker suffered a broken ankle and ligament damage in the Titans' loss to the Miami Dolphins on Sunday. He was carted off of the field in the fourth quarter. Walker had four catches for 52 yards before leaving the game.
The Titans signed tight end MyCole Pruitt in a corresponding transaction.
Walker, 34, was playing in his 13th season. The three-time Pro Bowl selection had 807 yards and three touchdowns on 74 receptions in 16 games in 2017. He also saw 11 targets. Walker had four consecutive seasons with at least 800 receiving yards entering his 2018 campaign.
"I hope he gets back as fast as he can," Titans quarterback Marcus Mariota said after Sunday's setback. "That guy's a stud. He's been Mr. Reliable throughout his entire career and whatever happens we got to have the next guy step up. But hopefully speedy recovery and he'll be back."
Titans coach Mike Vrabel said his thoughts and prayers went to the veteran pass catcher.
"It certainly didn't look good where I was standing and I'm sure it didn't look any better from where you guys were either," Vrabel said.
The tight end signed a two-year, $17 million contract extension this offseason. Walker is expected to undergo surgery in the next few days, according to Vrabel.