Ryan Tannehill already was wearing a brace on his left knee after last year’s season-ending injury. (Taimy Alvarez/South Florida Sun-Sentinel via AP)

The Miami Dolphins and Ryan Tannehill will wait for further medical opinions, but ESPN’s Adam Schefter reported late Thursday that the team fears its starting quarterback will need season-ending surgery on his left knee after suffering a noncontact injury in practice Thursday morning.

“He’s done, I think,” a source told Schefter, who added that Tannehill and the team could decide to rest the knee for six to eight weeks and hope it heals on its own. But the Dolphins “are growing increasingly concerned that surgery will be the most viable and likely option,” the ESPN reporter says.

Tannehill did not have surgery on the same knee when he went down in December with a partially torn ACL, instead choosing a stem-cell treatment, and a source told Schefter that his knee was “a ticking time bomb that was going to go off at any time” because of that decision.

Tannehill received the results of an MRI on his left knee after he limped off the field during a training-camp practice Thursday morning. And while he did not come down with any full tears, he did reportedly suffer a “setback.”

ESPN’s Jeff Darlington had more:

And while the team continues to await more test results on the quarterback’s knee — one in which he initially sprained the ACL and MCL last December, but did not need surgery — team officials still realize it might be the best long-term solution to have Tannehill undergo a procedure that would fully repair the partially torn ligaments. Such a scenario probably would end his season, and team sources say that scenario remains on the table.

For now, Matt Moore will be Miami’s new No. 1 quarterback, but both Schefter and Darlington report that Jay Cutler might be willing to resume his NFL career in Miami instead of heading to the Fox Sports broadcasting booth. Cutler played well under Dolphins Coach Adam Gase with the Bears in 2015. However, both ESPN reporters say Cutler would only consider the move if he was guaranteed the starting spot and was given a starting quarterback’s salary, and that the Dolphins haven’t begun to consider bringing in anyone new quite yet.

Colin Kaepernick’s name also has been bandied about as an insurance plan by the Dolphins’ front office, according to ESPN’s Josina Anderson. However, Kaepernick might not be the most popular move in an area with a sizable Cuban population, given the controversy that was generated when he wore a T-shirt bearing the image of Fidel Castro and engaging in a back-and-forth with a Miami Herald reporter about Castro. Kaepernick has praised the late Cuban leader for investing more in education than in prisons, saying that contrasted with U.S. policy. He went on to add that, “Trying to push the false narrative that I was a supporter of the oppressive things that he did, it’s just not true.”

Tannehill had scrambled to the sideline during the team’s first 11-on-11 session, then fell awkwardly on his left leg, on which he wears a brace from an injury he suffered in December. He immediately left the field, the Sun-Sentinel’s Omar Kelly reported, and was described by the Miami Herald’s Armando Salguero as walking “gingerly” to the locker room with trainers.

Tannehill, at a minimum, hyperextended the knee, Salguero reports, and there may be posterior cruciate ligament damage as well.

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