A month after the Bills running back conducted a weeklong hold-in during training camp that ended when Buffalo signed him to a four-year, $48 million contract extension, Cook has begun validating his worth three weeks -- and three wins -- into the season.

Though the five-time defending AFC East champion Bills are unquestionably Josh Allen's team, the fourth-year running back has played a critical role in an offense that's averaging 420 yards and has topped 30 points in each outing.

Cook leads the league entering the weekend with four rushing touchdowns, one ahead of Indianapolis quarterback Daniel Jones. With his 2-yard TD in a 31-21 win over the Miami Dolphins on Thursday night, Cook matched a Buffalo record by rushing for a score in seven straight games.

And with 108 yards rushing against the Dolphins, he ended Miami's NFL-best streak of games without allowing a 100-yard rusher at 35.

"He looks like he's been shot out of a cannon every time he touches it. He's so fun to play with," Allen said. "He's been such a catalyst for our offense. Special player."

To think, the Bills' initial offer to Cook came in averaging about $8 million a year, with general manager Brandon Beane initially willing to wait until the offseason to renew discussions after talks broke down in April.

Even so, the Bills may have gotten a bargain by signing Cook to a contract that currently ranks seventh among NFL running backs with an average salary of $12 million per year, according to Spotrac.

Coach Sean McDermott chuckled at the question of whether Cook is underpaid.

"From the coach's lens, I understand why we extended James," McDermott said Friday. "I think he's one of the better running backs in the NFL."

Cook brings power and elusiveness, adds balance to what had previously been a pass-heavy attack, has a pass-catching dimension and reduces Allen's role -- and the hits the quarterback takes -- in the run game.

While Buffalo's young, injury- and suspension-depleted defense struggled against Miami -- the Dolphins converted 10 of 15 third-down opportunities -- the offense is clicking on a team with Super Bowl aspirations.

Allen, the reigning MVP, has yet to turn the ball over. And he's carried over Buffalo's share-the-wealth approach from last season by using his entire complement of receivers. Five players, including Cook, have at least eight receptions, and rookie tight end Jason Hawes is one of four to catch at a touchdown pass.

A year ago, the Bills opened the season facing questions about whether they had an offensive player who could take a lead role after Stefon Diggs was traded to Houston. Those concerns lingered this year.

Cook, who co-led the NFL with 16 rushing touchdowns a year ago, is proving to be the answer.

Scoring early. The Bills have scored touchdowns on each game-opening drive this season, and they have two TDs and a field goal on their first drives of the third quarter. Buffalo improved to 10-1 when scoring on its opening drive dating to the start of last season.

Third-down defense. A week after the Jets went 0 of 11 on third-down opportunities against Buffalo, Miami's 66.7% conversion rate marked the third time in 11 outings -- including playoffs -- opponents have converted two-thirds or more of third-down attempts.

Deone Walker. The rookie defensive tackle, filling in for injured starter Ed Oliver, raised his arms to get a piece of Tua Tagovailoa's pass attempt that was intercepted by linebacker Terrel Bernard. The victory-sealing play came with three minutes left and the Dolphins lined up at Buffalo's 21 and trailing 28-21.

Matt Prater. The veteran kicker pushed a 39-yard field-goal attempt wide left that would have put the Bills up 17-7 in the second quarter. Prater, filling in for injured Tyler Bass, did hit a 48-yarder with 22 seconds remaining.

It's too early to determine whether Oliver (left ankle) or starting linebacker Matt Milano (pectoral) will be able to resume practicing next week.

13-0 -- Buffalo's regular-season record at home since a 24-22 loss to Denver on Nov. 13, 2023.

Get a mini-break before hosting the New Orleans Saints on Sept. 28.

Bills running back James Cook is already validating his new contract 3 weeks into the season