Source: Indianapolis Colts guard Quenton Nelson agrees to record 4-year extension

Indianapolis Colts Pro Bowl offensive lineman Quenton Nelson has agreed to a record-setting, four-year extension that will make him the highest-paid guard in NFL history, a source told ESPN's Adam Schefter.

The deal has an average annual value of $20 million and includes $60 million guaranteed, the source said.

The Colts announced they had agreed to terms on an extension Saturday night, with owner Jim Irsay calling Nelson "a generational player."

Nelson, who was scheduled to make $13.8 million this season, was set to be one of the top free agents in the 2023 class. His deal shatters the previous record for most guaranteed money and annual salary for a guard.

Drafted sixth overall in 2018 out of Notre Dame, Nelson had been an All-Pro guard in each of his first three seasons before missing four games this past year with an ankle injury.

Nelson's 94.1% pass block win rate was 12th among guards last season, and his 71.7% run block win rate was 13th at the position. Overall, Nelson's 94.6% pass block win rate since entering the NFL in 2018 ranks seventh among guards.

"Everyone knows what great ability he has, but I think what makes Quenton special is how smart he plays and how instinctive he is," coach Frank Reich said in a statement. "I think that's what takes his game over the top. He's a physically dominant player, but it's his instincts and his intelligence that take him I think to another level."

Nelson is the sixth member of the Colts' 2018 draft class to sign a second contract with the team.