FLORHAM PARK, N.J. -- Defensive end John Franklin-Myers, one of the New York Jets' promising young players on defense, has agreed to a contract extension, it was announced Friday.

Terms were not disclosed, but a source confirmed to ESPN that it is a four-year extension worth $55 million, including $30 million guaranteed.

The 25-year-old Franklin-Myers was in the final year of his rookie contract, making $920,000 in 2021. The extension puts him under contract through 2025.

"He's done nothing but work, work, work," coach Robert Saleh told reporters in London ahead of Sunday's game against the Atlanta Falcons. "He's been a tremendous leader and then you see his play on the field. He's absolutely dominant at times. ... He hasn't even scratched the surface of where we think he can go in this system. Those are the guys you want to pay."

Franklin-Myers, claimed on waivers from the Los Angeles Rams in 2019, won a starting job in training camp. In four games, he has three sacks, tying a career high, along with five quarterback hits and one forced fumble.

The Jets like Franklin-Myers because of his versatility; he can play inside or outside on the defensive line.

"I would anticipate him having a really good year for us, a career year for himself," defensive coordinator Jeff Ulbrich said recently.

Franklin-Myers was a fourth-round pick of the Rams in 2018. As a rookie, he played in the Super Bowl and recorded a strip sack of Tom Brady in the Rams' loss to the New England Patriots.

Surprisingly, Franklin-Myers was waived the following preseason. The Jets claimed him, but he wound up on injured reserve. In 2020, he emerged as a key part of the defensive-line rotation, recording three sacks.

General manager Joe Douglas is a believer in building a team through the defensive and offensive lines. He signed free agent Carl Lawson to a three-year, $45 million contract, but he suffered a season-ending Achilles injury in training camp. He also signed Sheldon Rankins for two years, $11 million.

The next big contract will be Quinnen Williams, the third overall pick in 2019, but he's not eligible for a new deal until after the season.

The New York Daily News first reported on Franklin-Myers' four-year extension.