The Los Angeles Rams are living proof that the National Football League is a quarterback's league. It took Matthew Stafford one season to lead them to a Super Bowl win after years of dealing with Jared Goff's shortcomings.

You need a good quarterback to win. It's as simple as that. One mediocre QB might do the job here and then, and you could even make the playoffs — yes, we're looking at you, Jimmy G — if you have a good team, but you won't win when it matters the most.

That's because the QB carousel is always a big story every season. The guy who starts Week 1 may not make it to Week 6. With that in mind, let's take a look at the top 3 veteran QBs at risk of losing their job.

NFL News: 3 Veteran QBs Who Might Lose Their Starting Job By Midseason

3. Marcus Mariota

Marcus Mariota failed to live up to the hype as a former second-overall pick. He wasn't the dual-threat, explosive QB he was in Oregon and wound up losing his job to Ryan Tannehill of all guys. That's how bad things got.

He now has another shot at being a starter after backing up Derek Carr for a couple of years. However, the Atlanta Falcons are high on Desmond Ridder, and they may not need a lot of excuses to give their future QB a chance to audition for the job.

2. Ryan Tannehill

As we mentioned before, Ryan Tannehill is only starting because Marcus Mariota was even worse. But truth be told, it doesn't get any more 'mid' than him. While he's not the worst guy you could have at QB, he's not particularly good at anything, either.

Malik Willis balled out in college, and some believe he could be the best QB prospect in his class. He was quite impressive in the preseason, and the Tennessee Titans might turn to him if their offense struggles without A.J. Brown.

1. Mitch Trubisky

The fact that Mitch Trubisky and Kenny Pickett both beat Mason Rudolph in the depth chart speaks volumes of how terrible Rudolph is, but it's not like Trubisky is a significant upgrade. If anything, it was shocking not to see them start their prized rookie.

Trubisky's numbers aren't that bad, but his well-documented shortcomings, meltdowns, and avoidable mistakes are a big red flag. The Pittsburgh Steelers have a potential star on their hands in Pickett, so he should be behind center at some point in the season.