One of the biggest reasons many expect Philip Rivers to rebound with the Indianapolis Colts in 2020 is the sizable upgrade he'll have along the offensive line. Now, the Colts have ensured one of the key pieces of that line will be in town for the long haul. The team announced Thursday that it has signed Pro Bowl center Ryan Kelly to a contract extension, with ESPN's Adam Schefter reporting the deal is for $50 million over four years, making the Alabama product the NFL's highest-paid center.

Drafted 16th overall by the Colts in 2016, Kelly was set to enter the final year of his rookie contract and will now get $34 million guaranteed on the new deal, per Schefter, which keeps him in Indy through 2024. In terms of average annual salary, Kelly now ranks first among all centers with a $12.5 million mark from 2021-2024, eclipsing Rodney Hudson ($11.25M), Mitch Morse ($11.125M), Nick Martin ($11M) and Maurkice Pouncey ($11M). He'll earn $10.35M in 2020 under the Colts' fifth-year option.

After starting all 16 games as a rookie, Kelly missed all but seven contests the following year due to multiple injuries, then sat out an additional four games in 2018. When healthy, however, the former Crimson Tide standout has been a well-renowned pass blocker at the heart of the Colts' O-line, earning his first Pro Bowl bid in 2019 thanks to another full 16-game slate.

Kelly is one of three former first-rounders starting in the Colts' trenches. Alongside longtime left tackle Anthony Castonzo, two-time Pro Bowl left guard Quenton Nelson, right guard Mark Glowinski and up-and-coming right tackle Braden Smith, he helps make up one of the highest-graded blocking units in the league.