An odd afternoon in Miami became a difficult one for Tennessee.
Walker suffered a dislocated ankle and an associated fracture, almost certainly ending his season, NFL Network Insider Ian Rapoport reported.
Walker's injury came late in the fourth quarter when a defender fell awkwardly on his leg as he went down to the ground. He was carted off the field, and based on Rapoport's reporting, Jonnu Smith's responsibility will increase dramatically in Walker's absence.
Blaine Gabbert replaced Mariota and led a touchdown drive after the second weather delay, but when Tennessee needed points late, the absence of Mariota was obvious. The Titans failed to put together a meaningful drive on their final two possessions when trailing by 10, managing to score just three points on a field goal with less than 20 seconds left.
Mariota explained why he couldn't continue after the game.
"Just couldn't feel my fingers," Mariota said. "Couldn't feel my hand."
Tennessee has one of the league's better offensive lines, but a lot of that is due to Lewan. Without him (and Jack Conklin, who was inactive due to injury Sunday), the Titans are instead forced to play backup guard Kevin Pamphile at left tackle and backup Dennis Kelly at right tackle. With Mariota banged up, his starting tackles out of action and Walker likely done for the season, things could get dire rather quickly for the Titans, who might be forced to immediately weather three incredibly important losses.