INDIANAPOLIS — The Colts have spent most of the offseason focused on keeping the homegrown core of a roster they believe is on the brink of taking the next step.

Indianapolis followed that up by making sure the best outside acquisition of general manager Chris Ballard’s tenure isn’t going anywhere for a while, either.

Defensive tackle DeForest Buckner signed a two-year contract extension worth up to $46 million, multiple people familiar with the deal told IndyStar and the USA TODAY Network on Monday morning. The people spoke on condition of anonymity because they were not authorized to disclose financial terms of the agreement.

The move ties the star defensive tackle to Indianapolis through the 2026 season, although it’s unclear if the structure of the deal frees up any space for the Colts, who had more than $14 million available before the deal, according to NFLPA records. Full details of Buckner's extension are not available yet.

“DeForest has been the epitome of what it means to be a Colt the last four years,” Ballard said in a statement released by the Colts.

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The trade that originally brought Buckner to Indianapolis remains an outlier in Ballard’s eight offseasons in charge of the Colts.

Focused primarily on rewarding his own locker room, Ballard has made a handful of significant outside investments in the roster during his tenure, most notably a string of highly-paid veteran quarterbacks and a couple of established defensive stars like Justin Houston and Stephon Gilmore.

But the Buckner trade was different, the only time Ballard has given up significant draft capital and a top-of-market extension to get one of the NFL’s best players at his position.

Buckner was the rare player Ballard was convinced would be worth the cost.

A standard that has proven to be remarkably difficult to reach.

Ballard places a premium on the message that the team’s financial and roster decisions send to the rest of the locker room, and for that reason, he has long said that any player signed to big money from the outside has to prove he deserves it, on and off the field, because the rest of the Colts will be watching. When Ballard traded for Buckner and made him one of the NFL’s highest-paid defensive tackles, he was betting on both the San Francisco star’s play and his reputation.

Buckner has rewarded Ballard’s faith handsomely.

“As one of the premier defensive tackles in the league, he is a destructive force on our defensive line,” Ballard said in a statement. “DeForest is one of the pillars of our locker room. His hard work, consistency and approach to the game are vital to the success of our team. We are fortunate to have DeForest and the caliber of man he is representing our organization.”

Buckner has as spent most of his four years in Indianapolis as the team’s lone elite pass rusher, averaging eight sacks and 21.75 quarterback hits while earning two Pro Bowl nods and a first-team All-Pro berth in his first season in 2020.

He has also been much more than a pass rusher.

Buckner has averaged 70.25 tackles per season and 10.5 tackles-for-loss in his four seasons in Indianapolis, a remarkable number for a defensive tackle, topping out with a career-high 81 stops in 2023. He has also been incredibly consistent, missing only one game in his Colts career — due to a positive COVID test in 2020 — while playing through a dislocated joint in his right hand in 2021, a torn UCL in his left elbow in 2023, as well as a bad ankle sprain and a significant back injury.

He simply keeps showing up, and his effort has set the tone for a pass rush that set an Indianapolis-era record by racking up 51 sacks last season.

“Buck sets the tone for the effort,” defensive end Samson Ebukam said last season.

Buckner is now 30 years old, but his body type, durability and a history of defensive tackles like recently-retired Eagle Fletcher Cox playing well into their later years suggest he can continue to grow.

He is also the team’s unquestioned leader in the locker room, a critical piece who has stuck with the Colts even though the team’s collapse in 2023 left Buckner admittedly asking questions of Ballard about the team’s direction. Ballard convinced Buckner to stay, and the defensive tackle now forms the fulcrum of a defensive core that has been retained this offseason.

Ballard handed key extensions to Ballard and middle linebacker Zaire Franklin, signed slot cornerback Kenny Moore II and nose tackle Grover Stewart — Buckner’s running mate — to three-year extensions and brought back Julian Blackmon, retaining the core of the defense for the foreseeable future.

Indianapolis has not significantly added to a secondary that struggled last season yet, but the Colts also have not allowed any key veterans to leave, a move that would have opened a gaping hole in the defense.

Bringing back Buckner is the final piece of retaining the defensive core Ballard has built.

The final confirmation of Ballard’s belief in the decision to trade for him in the first place.