INDIANAPOLIS — The deal is done — and right before the start of the regular season.

The Indianapolis Colts announced today they have signed Ryan Kelly, their Pro Bowl center, to a contract extension. Terms of the deal were not immediately released.

Kelly, 27, has developed into one of the best players at his position across the league since being selected by the Colts in the first round (18th overall) in the 2016 NFL Draft. The Alabama product has started all 51 games in which he has appeared over the last four seasons, including all 16 last year, when he was selected to his first-career Pro Bowl.

With Kelly — whose fifth-year option was picked up by the team last year — entering a contract year in 2020, the Colts stayed in contact with his representatives throughout the offseason to begin working out an extension for the "alpha dog" leader of their talented offensive line, as described by head coach Frank Reich.

Since Reich's first season in 2018, the Colts have allowed the third fewest sacks in the NFL (50), and have the ninth-most rushing yards (120.3 per game).

"He has been top-notch," head coach Frank Reich said in May when asked about what Kelly has meant to the team. "I mean, this guy has taken complete control of the offensive line room as far as the calls — what we do in the protection world and the run game. He is a really, really smart football player. He prepares very hard.

"I just think Ryan breeds confidence," Reich continued. "I just think when you hear him make the calls you hear it with authority, you hear it with conviction. I think the offensive line feeds off of that."

Kelly started all 16 games his rookie season in 2016 before working through some injuries in 2017 (nine games missed) and 2018 (four games missed). He bounced back in 2019 in a big way, however, starting all 16 games once again and turning in the best season of his career.

Anchoring one of the league's top all-around offensive lines — the Colts ranked seventh overall in rushing last year, while the team's sack percentage ranked tied for eighth in the NFL — Kelly earned Pro Football Focus' sixth-highest grade among all league centers (73.0).

His 74.6 run-blocking grade was fourth at the position, and he was only one of seven full-time centers to allow one or fewer sacks on the year.

Kelly in 2019 became the first Colts center named to the Pro Bowl since Jeff Saturday in 2010, and the fifth center in franchise history to be selected to the league's annual all-star game, joining Saturday (five Pro Bowl selections), Ray Donaldson (four), Bill Curry (two) and Dick Szymanski (four).

Kelly's extension ensures the Colts' starting five offensive linemen — left tackle Anthony Castonzo, left guard Quenton Nelson, Kelly at center, right guard Mark Glowinski and right tackle Braden Smith — are under contract with the team through at least the 2021 season.