After a week filled with optimistic comments on the status of quarterback Marcus Mariota, the outlook on his ability to start on Sunday against the Colts has suddenly turned grim.

While Mariota is officially listed as questionable with a neck and foot injury on the injury report, he’s primarily dealing with nerve issues caused by a stinger.

According to a report by ESPN NFL reporter Chris Mortenson, a spine specialist has warned the team that playing in the regular season finale could cause more than just temporary damage for Mariota.

“One source told ESPN that an independent spine specialist has warned the Titans that further damage would put Mariota’s ability to throw the football at significant risk beyond this weekend.”

Mortenson also elaborated to a point that implies experts believe it may be detrimental for Mariota to continue playing football as long as he’s being affected by the condition that has seemingly stayed with him all year.

“…it is the physical contact of a football game that would subject Mariota to the risk of permanent damage, according to the opinion of the independent spine specialist that has been shared with team officials and the medical staff.”

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Per the same report, the Titans still hold out hope that the quarterback can fully recover and still participate in the postseason with some rest and added recovery time.

As for Mariota’s foot injury, a source has clarified the signal-caller is suffering from a partially torn plantar fascia.

No one from the team has released a comment on the situation.

Backup quarterback Blaine Gabbert is expected to start against the Indianapolis on Sunday evening, with a newly signed Austin Davis behind him.