Marcus Mariota is presumed to the the starting quarterback when the Tennessee Titans begin the regular season Sept. 8. Could that presumption be wrong?

According to a report from ESPN football insider Dianna Russini, Mariota is “not a lock” to start for the Titans in Week 1. According to Russini, the Titans could shock nearly everyone and opt for current backup Ryan Tannehill to start when the Titans face the Cleveland Browns in their regular season opener.

“There’s a tone in Tennessee right now that this coaching staff just wants a quarterback to go out there and be the best quarterback there,” Russini said Monday on ESPN’s “Get Up." “Meaning it is not a lock that this is Marcus Mariota’s job.”

WATCH/LISTEN: I cut out and edited the report from Dianna Russini for easier consumption by everyone.



I'd pay closer attention to what she says than some of the other guys in this clip.



Curious, does this change your POV about Marcus's standing with the staff?



Let us know!👇 pic.twitter.com/BTMFaIWllI — Football & Other F Words (@FWordsPod) August 13, 2019

Whew. Russini cited Mariota and Tannehill’s performances Thursday during the Titans’ 27-10 win over the Philadelphia Eagles in their preseason opener.

Mariota, who played only during the opening series, completed 4-of-8 passes for 24 yards. Tannehill, signed by the Titans in March, completed 12-of-16 passes for 130 yards and two touchdowns. Of course, Mariota faced the Eagles’ starting defense while Tannehill produced his numbers against the backups. That reality didn’t deter Russini from continuing on her assessment.

“This doesn’t mean they have given up on Marcus Mariota. They want this to work. They know what he can be,” Russini said. “But Ryan Tannehill is stepping in here and he understands this offense. He has the experience, he knows how to win. This could be his job and we’re talking Week 1.”

Titans coach Mike Vrabel has consistently said Mariota is the starter and Tannehill is there to push Mariota. However, Mariota is in the final year of his rookie contract and is coming off back-to-back mediocre seasons in 2017 and 2018. The Titans have not offered him an extension, opting to take a wait-and-see approach in 2019.

-- Geoffrey C. Arnold | @geoffreyCarnold