If Matt Cassel was feeling the heat from first-round pick Teddy Bridgewater during the preseason, he didn’t let it show.

The veteran quarterback played with poise throughout training camp and the preseason, commanding the huddle and minimizing mistakes while convincing the Vikings that the future can wait. And now that he has secured the starting gig heading into Sunday’s season opener in St. Louis, Cassel isn’t looking back.

Besides, Cassel probably will be too preoccupied with the formidable Rams pass rush to worry about whether Vikings coach Mike Zimmer is instructing the rookie to buckle up his chinstrap over on the sideline.

“I think I’ve had a tremendous offseason. I’ve worked as hard as I’ve ever worked. And I’m not going to look over my shoulder,” Cassel said. “You can’t play that way. You can’t worry that if I make a mistake, what’s going to happen next? You’ve got to go out and play the game to the best of your ability.”

Like most coaches, Zimmer has pounded the pulpit while declaring that every starting position is up for grabs, though it remains to be seen if he will be one of the ones who actually walks the walk. But Zimmer did acknowledge Wednesday that while making changes at other positions may have a ripple effect on his team, the impact of swapping quarterbacks would be something closer to a tsunami.

“I don’t want to have a quick hook, but I do want to do what’s the right thing for the football team,” Zimmer said. “At that point in time, [offensive coordinator] Norv [Turner] and I will sit down and discuss it -- if it gets to that point.”

Zimmer made it clear, though, that he doesn’t expect it to get to that point any time soon.

Sure, the Vikings open the season with a gauntlet of playoff hopefuls. After playing All-Pro pass rusher Robert Quinn and the Rams, the Vikings will face the New England Patriots, New Orleans Saints, Atlanta Falcons and Green Bay Packers. Each of them will present unique challenges.

But Zimmer said he saw little from Cassel during spring workouts, training camp and the preseason to suggest he is going to face plant out of the starting gates.

“I don’t foresee that being an early decision,” Zimmer said. “We’ve gone seven, almost eight weeks now, and we feel like this is the way we want to go. So if he throws an interception on the first play of the game, I’m not going to yank him.”

Zimmer kept everyone hanging while he waited until after the third preseason game to name his starter, but anointing Cassel was pretty much a formality. He was sharp throughout the preseason as he distanced himself from Bridgewater, the 32nd overall pick in May’s NFL draft.

Cassel completed 66.7 percent of his preseason passes for 367 yards and two touchdowns with just one turnover. Bridgewater had a higher passer rating. But in yards per attempt — a more accurate measure of quarterback efficiency — Cassel was nearly 4 yards better than Bridgewater at 9.4.

Even though Bridgewater will hold a clipboard instead of a football Sunday — no word on whether he will wear his signature gloves for that — Zimmer and the Vikings are pleased with the progress he has made and still believe he will one day lead the franchise. It’s just that Zimmer and Turner, who also has input at the position, feel Cassel gives the Vikings the best chance to win now.

“I know the fans are excited about Teddy. I’m excited about Teddy,” Zimmer said. “But we have to do what’s best for the football team at this point in time and what’s best for the future. … As you know, coaches’ futures aren’t necessarily very long. I’m always trying to think between the now and the future and what’s best for this organization as we go down the road.”

Bridgewater estimated he is only getting about 2 percent of the first-team reps in practice this week. His time to shine is when he simulates the other team’s quarterback while running the scout team.

“The preparation changes as far as practice because we have to get Matt ready for this upcoming game,” Bridgewater said. “We have to get Matt ready to play. So for me, I won’t be getting as many reps as I received in the preseason. But for me, it’s all about taking advantage of those reps that I do get.”

Bridgewater has praised Cassel, who has a 32-36 career record as a starter, and former Vikings quarterback of the future Christian Ponder for mentoring him throughout the spring and summer.

But while Cassel isn’t going to tell the kid to scram if he has a question now that the season has started, he did say his main focus will be preparing himself — not his potential successor — to play so he can win games and keep Bridgewater’s helmet unbuckled on the sideline.

“I think Teddy does have a tremendous future,” Cassel said. “But hopefully, as long as I’m here, he’s not playing.”