As DeForest Buckner's career trajectory climbed to an All-Pro level, so did his value, which the Indianapolis Colts were more willing to meet than the 49ers, a league source confirmed.
In a shocking trade, the 49ers agreed to deal the fourth-year defensive tackle in exchange for the Colts' first-round draft pick, No. 13 overall on Monday.
Buckner will garner $21 million annually on his new deal, according to ESPN and NFL Network.
That news broke just as the 49ers confirmed signing a multi-year deal with Arik Armstead, who had been Buckner's teammate since their University of Oregon days and preceded him as a 49ers' first-round draft pick.
The trade can not become official until the league year starts Wednesday at 1 p.m., so the 49ers are not expected to confirm nor comment on it. Buckner's agent, Joel Segal, did not immediately return a request seeking comment, but Buckner confirmed the news via social media.
"I want to thank the 49ers for taking a chance on me four years ago. It's been one hell of a journey, from 2-14 my rookie year to the Super Bowl this past season," Buckner wrote, addressing coaches, teammates, staff and fans. " I just want to thank you all for helping me grow as a man, friend and teammate. The Faithful will always have a special place in my heart.
"Colts Nation, I can't wait to get this thing rollin.' I'm bringing everything I got to Indy!!"
Buckner was to make $12.3 million this season on the fifth-year option of his rookie deal. Now he will be the league's second-highest paid defensive tackle behind the Los Angeles Rams' Aaron Donald.
The 49ers now have two first-round draft picks, Nos. 13 and 31. That tradeable equity helps offset the loss of their second-, third- and fourth-round picks they traded away last year for wide receiver Emmanuel Sanders and defensive end Dee Ford.
Buckner has gradually gained recognition around the league, and his influence on a dynamic defensive front last season led to Associated Press' Second-Team All-Pro honors. His interior presence was unmistakable while being complemented by fellow linemen Armstead, Ford and Nick Bosa.
The 49ers' coaches thought so much of Buckner they named him the Bill Walsh Award winner, an MVP-like honor that represents the standard of professional excellence instituted by the former coach.
After totaling a career-high 12 sacks in 2018, Buckner had 7 { this past regular season and 2 { in the playoffs, including 1 { in the Super Bowl loss to the Kansas City Chiefs. He recovered five fumbles on the season, the last coming in the NFC Championship Game against Green Bay's Aaron Rodgers.
Rather than hit free agency, Armstead scored a five-year deal worth up to $85 million, NFL Network reported. Still headed for free agency are wide receiver Emmanuel Sanders, safety Jimmie Word and nearly a dozen other 49ers.
