Quarterback Marcus Mariota is "close" to being ready to return to action but will be held out for a second consecutive week coming off a knee injury, the Tennessee Titans announced Friday.

Zach Mettenberger will start in Mariota’s place Sunday at Houston.

"Marcus (Mariota) has made a lot of progress this week. He’s done a nice job, I think he’s close, but we’re not going to play him this week," Titans coach Ken Whisenhunt told the media Friday. "I think that’s the best decision for him and that’s what we’re going to go with."

Mariota suffered a sprained left knee two weeks ago on a controversial hit by Miami defensive end Olivier Vernon in a 38-10 loss to the Dolphins. Vernon was fined $37,363 by the NFL for two hits on Mariota.

Mariota sat out last week’s game at Atlanta, the first he’s missed in four years as a starter, three of them at the University of Oregon.

Whisenhunt said holding Mariota out this week was due more to missed practice time than the injury. "I think probably just missing some reps. I think physically he’s probably on the line of being ready to go, but it’s a tough enough position to play without getting the bulk of the reps," Whisenhunt said. "That was part of it."

Asked if Mariota would definitely play next week at New Orleans, Whisenhunt said, "You’ve got to be careful about saying those things because you don’t know if something could change. But where we are today, just what I said, it’s more of a function of not having gotten enough in practice to feel comfortable with him."

Asked if it was frustrating to have Mariota miss time in his rookie year, Whisenhunt said, " ‘Frustrating’ is not the right word. You feel bad for the kid because he wants to play so badly, but in the NFL season, you lose players. That happens. You’re just glad that he’ll be back and you go forward."