If the Dolphins are going to win their first playoff game since 2000, they'll have to do it without franchise quarterback Ryan Tannehill.

According to Dolphins.com's Alain Poupart, Tannehill won't play Sunday in Pittsburgh against the Steelers in the AFC wild-card matchup.

The 2012 first-round pick has been sidelined since Week 14, after Cardinals defensive lineman Calais Campbell hit him low. The results: Tannehill suffered a partially torn ACL and Grade 2 MCL sprain in his left knee. This was better than the initial fear of a completely torn ACL, but the four weeks between injury and playoff game isn't enough time to get Tannehill back on the field.

The Miami Herald's Armando Salguero reports that the Dolphins were hoping Tannehill could practice on Wednesday, and when that didn't happen, Thursday.

But in on-field workout sessions for Tannehill that Gase witnessed, the quarterback never looked quite right. He still has not regained enough mobility. He still has not found the comfort level to even practice.

Another concern: Tannehill's ACL is partially torn but it's still torn. Put another way: He could do more damage -- like, tear it completely -- if he comes back too soon. And that would not only end his 2016 season, but also put the start of the 2017 season in jeopardy.

(Quick history lesson: Back in 2012, Robert Griffin III played with a ligament sprain in the Redskins' playoff game against the Seahawks, made things worse in the process, spent the entire offseason rehabbing, came back too soon in 2013 and his career went south from there.)

Gase conceded Wednesday that "unless something changes drastically" Matt Moore would make his fourth start in place of Tannehill.

"I'm not really going to listen to him saying he wants to play," the coach said. "I know he wants to play. I'm pretty sure he had some medical classes in college, but I know he doesn't have a degree quite yet."

Tannehill has had a resurgence under Gase, but the Dolphins will need to rely on running back Jay Ajayi, who shredded the Steelers for more than 200 yards back in Week 6, if they're going to have a chance. Vegas has Pittsburgh favored by 10 points. And if that happens, who knows, maybe we'll see Tannehill next week in Foxborough against the Patriots.