now considers himself a grownup.

That hasn’t always been the case, especially during his first two seasons in the .

Tunsil said his performance in 2017 was the worst season of his playing career, and the left tackle openly admitted it triggered a metamorphosis, a maturation that the 24-year-old believes will help him become the All-Pro talent he has the potential to be.

“It’s not about showing everyone else. It’s really about proving it to myself,” said Tunsil, whose Dolphins (6-6) face the (9-3) on Sunday in a game that has playoff implications for both teams. “I don’t care what the people outside this building have to say. I’m trying to prove to myself I can be the best left tackle in the league, and that’s what I’m going to do.”

Last season, Tunsil moved to left tackle, sliding one spot over from left guard, the position he excelled at as a rookie. He struggled in 2017, allowing six sacks and being penalized eight times for false starts and holding.

His struggles weren’t glaringly noticeable, but he didn’t live up to expectations, which led to a soul-searching offseason that triggered significant growth on and off the field.

“I’ve matured,” said Tunsil, the Dolphins’ 2016 first-round pick whose draft stock plummeted after a draft-night video surfaced showing him smoking from a bong. “I’m taking care of my body. I’m watching film more. I’m in the playbook trying to understand everything.”

Tunsil credits veteran guard , who the Dolphins signed this offseason, for helping him become better prepared for the 2018 season.

Tunsil said Sitton taught him how to break down film, and showed him a few things he didn’t know about how to take care of his body. All those nuggets of wisdom have helped him perform better on game day.

As a result, Tunsil is one of two starting offensive tackles who haven’t allowed a sack with four games left in the season. The other player, Dallas offensive tackle , is a five-time selection.

“I wasn’t there mindset-wise,” said Tunsil, who has battled through a left knee injury this past month. “I’d watch film and be like, ‘whatever, whatever, whatever.’ Now I’m all up in it. I’m trying to learn everything step by step, every detail I can.

“I always look back to last year and [say] I don’t want to repeat last year. That was probably the worst football I played,” Tunsil said. “I wanted to change my mindset.”

Now the focus is on perfection, finishing the season without allowing a sack and helping the offensive line pave the way for a playoff push.

According to Pro Football Focus, Tunsil has been credited with allowing 10 hurries and four hits. The analytics site ranks him as the 24th best tackle.

Dolphins coach Adam Gase said the game has slowed down for Tunsil, and that going up against three-time Pro Bowl defensive end Robert Quinn in the offseason and training camp helped him sharpen his skills.

Tunsil’s remarkable turnaround became evident when the Dolphins no longer needed to provide him help when facing the likes of Khalil Mack and other top pass rushers.

“It lets me help all of the other guys. When you can just say, ‘he’s got him,’ we can double [others],” Gase said. “We’ve got the center and the guard doubling a guy and then we can use a tight end and a tackle to double the other guy. You can get double teams across the board if you can leave him on an island.”

And that’s what Miami has been doing.

“I think Tunsil has played very well. I’ve been extremely impressed with him. He’s as good of a left tackle as I’ve ever been around,” said offensive coordinator Dowell Loggains, who put Tunsil in the company of legend and , a 10-year starter for the Tennessee Titans, both of which he coached.

“As a young player, there’s some things he needed to get out of his game,” Loggains added. “We’re still working hard to eliminate some penalties and [creating] consistency with technique, but he’s a really good player and we expect him to keep getting better.”

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