NASHVILLE, Tenn. >> Titans quarterback Marcus Mariota showed his toughness, staying in the game and not missing a play despite spraining his left MCL. Now Tennessee will see how quickly the Heisman Trophy winner heals.

Coach Ken Whisenhunt said today an MRI exam showed Mariota sprained the MCL in his left knee when hit low by Dolphins defensive end Olivier Vernon during the second quarter of a 38-10 loss to Miami.

The Titans wrap up a rare four-game home stand Sunday when they host Atlanta (5-1).

“From what I’ve seen of him walking around today, he’s moving around fine,” Whisenhunt said. “So we’ve got to see it on the field to be able to see what he’s able to do, and that’ll happen we think Wednesday.”

Team trainers and a doctor examined Mariota on the field after the hit. Mariota took advantage of a roughing the passer penalty on Vernon to avoid missing even a play. Trainers helped Mariota put on a brace after that series, and he played until Whisenhunt sent Zach Mettenberger in for the final series with 1:54 left.

The Dolphins sacked Mariota five times by halftime. The rookie also lost two fumbles before halftime and was intercepted twice in the second half, but Whisenhunt said Mariota was able to move around in the pocket after the injury.

“He’s a tough kid, and I know he didn’t want to come out,” Whisenhunt said. “So you’ve got to make sure that the toughness doesn’t cloud your thinking and put him in there at risk. I didn’t feel like from talking with the trainers and talking with Marcus that that was the case.”

The Titans (1-4) have to figure out how to split the work in practice to give Mariota the best chance at both healing up and being ready to play Sunday while also preparing Mettenberger in case he must start.

“We’ll split the reps accordingly based on what we think Marcus can do,” Whisenhunt said. “Some of it may be determined by Wednesday and what he can actually do on the field.”

The Titans have struggled protecting their rookie quarterback. Mariota has been sacked 19 times through five games, tied for third-most with Colin Kaepernick of San Francisco. Mariota has lost a league-high four fumbles.

Protecting Mariota will be a bigger challenge with center Brian Schwenke lost for the rest of the season with a dislocated left ankle, His replacement for now is rookie Andy Gallik, giving the Titans two rookie starters on the offensive line with right tackle Jeremiah Poutasi.

“It’s got to be better than it was yesterday, and that has to happen this week,” Whisenhunt said.

The Titans have wasted this franchise’s longest home stand since the late 1960s, having lost four straight. Worse, their home skid now is eight consecutive games, and Whisenhunt is just 1-11 in Nashville since taking over last season.

“It stinks that we’re not better at home,” Whisenhunt said. “That’s something that it’s not fair to our fans, and we’ve got to do a better job of that.”

The schedule doesn’t get any easier for Tennessee when this home stand ends with three of the next four on the road. Carolina (5-0) visits Nov. 15, while December features back-to-back road trips to the Jets (4-1) and Patriots (5-0).

“We’ve just got to stick together and not break,” cornerback Perrish Cox said. “We know we’ve got to work for it. It’s not going to be easy. It’s going to be tough, but we have to keep pushing.”

Notes: Cox said he was having an MRI exam later Monday for his sore hamstring that limited him to eight plays against Miami. … S Michael Griffin limped out of the locker room with a sore knee, and Whisenhunt said they’ll see where the veteran is Wednesday.