Tight end Darren Waller and the Las Vegas Raiders have reached agreement on a three-year contract extension with $51 million in new money.

"This was one of the most challenging negotiations I've encountered," said Walker's agent Drew Rosenhaus. "It is very rare for a 30-year-old player with two years left on his contract to get a new deal."

Waller is now contractually tied to the Raiders for five years and $66.25 million. He had two years left on the four-year, $29.8 million extension he signed in 2019 but had no guaranteed money remaining. Waller was set to earn $7 million in each of the next two seasons.

Waller, who turns 30 on Tuesday, emerged as a premier tight end in 2019, when he had 90 catches for 1,145 yards and three touchdowns. He followed that up in 2020 with 107 catches, 1,196 yards and 11 touchdowns. Since becoming a starter in 2019, Waller ranks second in the NFL among all tight ends in catches and yards, trailing only Kansas City's Travis Kelce in both categories.

Waller was limited to 11 games last season due to injuries to an ankle, his left knee and his back, plus a positive test for COVID-19. He missed most of training camp because of an undisclosed injury. He returned to practice once on Aug. 17 but has been sidelined again since then with a hamstring injury, although he is considered ready to go for the team's Week 1 showdown against the Los Angeles Chargers.

The new deal comes after Waller signed with Drew Rosenhaus and Robert Bailey on Wednesday after cutting ties with Klutch Sports as his representation.

Information from ESPN's Paul Gutierrez was used in this report.