The Detroit Lions and Frank Ragnow have agreed to a four-year, $54 million contract extension that makes him the highest-paid center in the NFL, a source told ESPN's Adam Schefter.

Ragnow, 24, is entering his fourth NFL season after being drafted in the first round out of Arkansas in 2018. He has started all 45 games he has appeared in and earned his first Pro Bowl berth last season.

He had been under contract for two more seasons after the Lions exercised their fifth-year option on his deal last week.

After the NFL draft last weekend, Lions general manager Brad Holmes called reaching a long-term deal with Ragnow "extremely important."

"He is a foundational piece because Frank is a guy that plays the game the right way," Holmes said. "He's everything that we look for and what we want as a Lion."

The Lions' front office views Ragnow as an important long-term piece as the team looks to shift its culture. This deal aligns with the Lions' latest draft picks and offseason decisions as they try to build for the future, including drafting Oregon offensive tackle Penei Sewell and adding veteran players to surround new quarterback Jared Goff such as free-agent tight end Darren Fells, who spent the past two seasons with the Houston Texans.

Ragnow ranked fourth among qualifying centers in run block win rate and seventh in pass block win rate last season, according to ESPN Stats & Information.

He is the second first-round pick from the 2018 draft to sign a long-term extension, joining Las Vegas Raiders left tackle Kolton Miller.

"I'll never forget when it first got announced that I got the job -- Frank, he reached out immediately," Holmes said. "I told him, I said, 'Man, huge fan of you. You play the game the right way.'"

He is now being rewarded.

ESPN's Eric Woodyard and The Associated Press contributed to this report.