Jemele Hill is happy Derek Carr is getting an extension, but isn't sure he deserves to be one of the game's highest-paid players. (1:20)

Quarterback Derek Carr tweeted Thursday that he has finalized an extension with the Oakland Raiders. Sources tell ESPN's Adam Schefter the five-year deal is worth $125 million.

Now it's done 😂! From the jump I've wanted to be a Raider 4 life. One step closer to that! Blessed!!! Business done! Let's just play now!!! — Derek Carr (@derekcarrqb) June 22, 2017

Carr, 26, is now under contract through 2022. His extension's average salary of $25 million will make him the NFL's highest-paid player in terms of new money average, a source told ESPN's Dan Graziano. Indianapolis Colts quarterback Andrew Luck had topped the list at $24.6 million.

Drew Brees' average annual salary is $24.25 million for New Orleans, and Kirk Cousins' is $23.9 million for Washington. Cousins and the Redskins are trying to get a long-term deal done by the July 17 franchise deadline.

A source told Graziano that Carr receivers $40 million fully guaranteed at signing. He also has a $30.2 million guarantee for injury only at signing, the source said.

A breakdown of the rest of the contract, according to the source:

Carr will make $25 million in Year 1 ($12.5 million signing bonus, a $7.5 million roster bonus paid on June 30 and a $5 million base salary.

In 2018, he has a $15 million roster bonus fully guaranteed at signing. His $7.4 million 2018 base salary becomes fully guaranteed in February of that year. He also has a $100,000 workout bonus in 2018 and each subsequent year of the deal.

In 2019 he has $20 million guaranteed for injury at signing and it becomes fully guaranteed in February of that year.

The remaining injury guarantee (about $3 million) is part of his 2020 salary, which is around $20 million, as are his non-guaranteed 2021 and 2022 salaries.

Raiders head coach Jack Del Rio and offensive coordinator Todd Downing were among the team's players and personnel to offer congratulations to Carr on Twitter.

Congrats w extension!! Continue to be the great teammate and leader you R. God Bless you & your family! #RaiderNation #ReturnToGreatness https://t.co/HJWmhdvrUR — Jack Del Rio (@coachdelrio) June 22, 2017

You won't find a harder working or more deserving man than @derekcarrqb. Congrats! I am happy for you & your fam & excited for what is next! https://t.co/511hyZVOo9 — Todd Downing (@CoachTD) June 22, 2017

Former NFL quarterback David Carr, meanwhile, joked on Twitter that lunch was now on his brother.

5yrs 125million .... @derekcarrqb

You got lunch. — David Carr (@DCarr8) June 22, 2017

Derek Carr passed for 3,937 yards and 28 touchdowns with just six interceptions last season, helping lead the Raiders to their first postseason appearance since 2002. He suffered a broken fibula in Week 16 and missed Oakland's playoff loss to the Houston Texans, but he has been a full participant in the team's offseason activities.

Carr, speaking last week at the Raiders' minicamp, said he was happy to be "just playing ball again."

"The hardest part was taking the first rep, because the last rep you remember was like, 'Oh snap, I broke this thing,'" Carr said. "But as soon as the ball was snapped, it was a blessing. It kind of all went away."

ESPN's Paul Gutierrez contributed to this report.