IRVINE, Calif. — Todd Gurley was the key to the Los Angeles Rams’ offensive transformation last season, and the Rams have rewarded their star running back with a game-changing contract.

The NFL’s offensive player of the year agreed to a four-year, $60 million contract extension through 2023 with the Rams on Tuesday.

A person with knowledge of the deal, speaking on condition of anonymity because the terms weren’t publicly announced, confirmed to The Associated Press that Gurley’s contract extension contains $45 million in guaranteed money, a $20 million signing bonus and the NFL’s largest average annual value for a running back contract. ESPN first reported the terms.

General Manager Les Snead said the Rams wanted “to get ahead of the curve” by signing Gurley two years before his rookie contract expires. They’ve also set a new benchmark for running back salaries to secure a cornerstone of a team with Super Bowl aspirations.

Gurley isn’t due to report to training camp at UC Irvine until Wednesday. His first public reaction was to post a black-and-white Instagram photo of himself with a broad smile and the caption: “Amazing…”

Gurley was a league standout in his third NFL season while playing in first-year coach Sean McVay’s explosive offense. He finished second in the NFL with 1,305 yards rushing and 13 touchdowns while catching 64 passes for 788 yards and six more TDs.

Los Angeles placed defensive lineman Dominique Easley and rookie linebacker Obo Okoronkwo on the physically unable to perform list heading into training camp.

PATRIOTS: Wide receiver Malcolm Mitchell will not be with his teammates at the start of training camp this week after undergoing a procedure on his knee, according to a source. Mitchell has dealt with knee injuries since college and missed all of last season due to a knee ailment.

Although it’s not known as to whether or not this latest setback will cost Mitchell his season, it could very well conclude his career with the Patriots. According to a source, it’s possible that Mitchell is waived or released with an injury settlement before the start of the season.

TITANS: Tennessee released outside linebacker Kevin Dodd, an unceremonious finish for a former second-round pick who never came close to living up his draft position.

The Titans announced in a one-sentence release that they plan to cut ties with Dodd, the 33rd overall pick in the 2016 draft.

LIONS: Detroit put defensive end Ziggy Ansah on the physically unable to perform list.

The Lions also placed fullback Nick Badwen on injured reserve with a knee injury, signed linebacker Freddie Bishop and put wide receiver Andy Jones on the PUP list.

BILLS: Buffalo signed free- agent linebacker Keenan Robinson in filling out its 90-player roster two days before opening training camp.

Robinson has five seasons of NFL experience, including the past two with the New York Giants.