Raiders quarterback Marcus Mariota said the right things about being a backup to Derek Carr this year. And he may have known the right things to say because he heard Ryan Tannehill say the same things about him in Tennessee last year.

Last year, Mariota was the Titans’ starter, and when Tannehill arrived, everyone insisted that Tannehill was just Mariota’s backup. This year, Carr is the Raiders’ starter, and everyone is insisting that Mariota is just Carr’s backup.

But, as everyone learned in Tennessee last year, a starter is only the starter until he isn’t. And just as Mariota was benched for Tannehill, Carr could be benched for Mariota.

This week, Mariota said, “I’m going to do my best to support Derek in every possible way that I can.”

Last year, Tannehill said, “I’m going to try to help Marcus as much as I can.”

This week, Mariota said of whether he’ll get to play, “First and foremost this is Derek’s team, and I understand that. I understand that going in.”

Last year, Tannehill said of whether he’ll get to play, “I don’t try to think about that. I have way too much respect for Marcus, him as a player, him as a person.”

This week, Mariota said, “a strong, stable, supportive quarterback room makes that job a whole lot easier.”

Last year, Tannehill said, “we’re aligned in trying to push each other and make each other better. Ultimately, we want to help this team win.”

The bottom line is this: Tannehill was brought in to be Mariota’s backup — until Titans coach Mike Vrabel decided otherwise. And Mariota was brought in to be Carr’s backup — until Raiders coach Jon Gruden decides otherwise.