RENTON — George Fant’s crazy transformation from college basketball power forward to starting NFL left tackle will continue with him starting there again to begin this season.

Veteran Luke Joeckel will be next to him as the starting left guard.

And Justin Britt will be the Seattle Seahawks’ center in 2017 and beyond.

Head coach Pete Carroll confirmed all that Thursday following the team’s light practice indoors for Friday’s second preseason game, against Minnesota at CenturyLink Field.

“Luke Joeckel is going to start at left guard, and George is going to start at left tackle,” Carroll said, more firmly declaring what line coach Tom Cable had all but said the day before. “We think that’s a very good combination for the left side.

“I feel really good about that right now, going into this game… There is still a big battle going on on the right side, at both guard and tackle.”

But not at center. And there apparently won’t be for a few more years, at least.

Britt, 26, and the Seahawks announced a three-year contract extension Thursday afternoon. Carroll said just before noon that the team was “really close” to finalizing the deal. ESPN’s Adam Caplan reported it is worth $27 million, with $13.25 million due to him through 2018.

Britt confirmed the deal by reacting on his Twitter account with thanks to the Seahawks and their fans — and expressing now is the time to go get a Super Bowl ring.

Britt becomes the first offensive lineman drafted by Carroll and general manager John Schneider to get a contract extension in their seven-year-old era in Seattle. From Russell Okung to James Carpenter through J.R. Sweezy, the Seahawks under Carroll and Schneider have let their top blockers become free agents and sign with other teams for money far richer than this team has been willing to pay for blockers.

“I think it’s just a recognition and acknowledgement of the player and the teammate that he’s become for us,” Carroll said.

“And also the fact that we were able to do that in the offensive line, it is important to note that. I don’t want to try to dissuade you from thinking that. It’s a statement, that we want to make sure we are taking care of these guys. Justin has done everything we’ve needed him to do. And he’s been a great teammate.”

Carroll added: “I’m thrilled that we are able to reward him like this. It’s very much in line with all the things we’ve done in the past (with core players). It just happens to go to that spot, right in the center of it all. And I’m fired up about that.”

Thursday’s agreement with Britt is a preemptive move for the Seahawks. It keep their best offensive lineman from entering free agency and following similar riches on the open market that craves experienced, quality blockers — especially at the anchor spot of center.

The value of $9 million would place Britt tied with Atlanta’s Alex Mack as the league’s third-highest paid center, in average annual contract value. Brandon Linder’s average of $10.3 million with Jacksonville and Travis Frederick’s $9.4 million with Dallas are the only centers with richer annual deals.

That $9 million per year is a huge leap from the $891,000 Britt was to earn this year, the final one of his rookie deal he signed as Seattle’s second-round draft choice in the spring of 2014.

That leap matches the one in Britt’s previously unsettled career.

This time last year, he seemed to be on perhaps his last chance with Seattle. He started his debut season at right tackle, including in Super Bowl 49. When that season didn’t go so well there, Britt became the left guard for 2015. He moved to his third position in three years last summer, after the Seahawks tried Drew Nowak and Patrick Lewis to replace two-time Pro Bowl center Max Unger. Both Nowak and Lewis failed to solidify the line in 2015.

Seattle traded Unger and a first-round pick to New Orleans in the spring of 2015 to get star tight end Jimmy Graham. It took moving Britt to center last preseason for the Seahawks to find Unger’s replacement. Britt became the best player on the league’s youngest, cheapest offensive line, and was named perhaps the most unlikely alternate to last season’s Pro Bowl.

“He has been a fantastic leader for us up there. He had a fantastic season (in 2016),” Carroll said. “He’s played three spots for us. Started at tackle, guard and center now. He think he’s really in the best spot for him.”