NASHVILLE, Tenn. – Titans quarterback Marcus Mariota is "coming along very well," coach Mike Mularkey said during his press conference on Monday.

Mariota's availability for next Monday's game against the Indianapolis Colts might not be known until the day of the game, however.

Mularkey once again called Mariota day to day. Mularkey said Mariota, who was inactive on Sunday in Miami, has done more each day on a treadmill.

"Marcus is coming along very well," Mularkey said. "He has had a couple of good days of rehab, even last night getting back from the game, he came in here and did some things that were a plus, and the same thing today.

"… We're not going to do anything that is going to set him back. That's the first thing - I am not going to set him back. I am not going to put him on a timeline on which practice we are looking at (for him). It might be Wednesday, it might be Friday."

Matt Cassel would start again at quarterback if Mariota's can't go.

Cassel completed 21-of-32 passes for 141 yards against the Dolphins, with a touchdown and no interceptions. He was sacked six times.

"It would be Matt (as the starter), and everybody around Matt has to play better for Matt," Mularkey said.

Mariota was limited in practices last week because of a hamstring injury he suffered against the Texans. He said last Friday he's spent a lot of time rehabbing, and "first and foremost (my) goal is just to get healthy."

Brandon Weeden, signed last week, was Cassel's back-up against the Dolphins.

Mariota scored on two touchdown runs against the Texans – he turned on the jets on his 34-yard touchdown run, and he sprinted to the pylon – and made it – on a two-yard touchdown later in the game. Unfortunately, Mariota suffered a hamstring injury on his second score, and as a result he didn't finish last Sunday's game.

On the season, Mariota has completed 66-of-110 passes for 792 yards, with three touchdowns and three interceptions.

"Obviously the earlier the better," Mularkey said when asked when he'd like to make a decision on Mariota's availability. "But I'd say it could go all the way up to the game."