A former NFL linebacker who believed he suffered from CTE died by suicide this week, his company confirmed.
Jason Hairston, 47, founded the hunting apparel company KUIU after leaving professional football and became close friends with Donald Trump Jr. in recent years.
The hunting partners went on a fishing trip in Canada last month.
“Jason, I have no words. I will always remember our adventures and sharing a campfire with you. They will be some of my fondest experiences in the outdoors. You were and will continue to be an inspiration to all outdoorsmen and women for generations to come,” Trump Jr. wrote in an Instagram tribute Thursday.
“Thanks for the friendship and the memories buddy. I’m going to miss you,” he wrote.
Hairston’s company confirmed the death on its website.
“We are incredibly saddened to report that Jason Hairston, the visionary leader and founder of KUIU, was found dead at his home in Dixon, CA on Sept. 4, 2018. He took his own life,” the statement said.
Hairston is survived by his wife Kirstyn and two children. The family asked that anyone wishing to show support make a donation to CTE-related research at the Boston University Concussion Legacy Foundation, the company said.
Hairston played for the 49ers and Denver Broncos before his retirement from the NFL in 1996.
He later spoke openly about CTE, saying he was suffering symptoms associated with the degenerative brain disease found in athletes and other people with a history of repetitive brain trauma.
“I played linebacker, and the way I played the game, I led with my head. I played the way they tell us not to play now,” Hairston reportedly told CNBC in 2016. “I have all the symptoms of CTE.”
According to a Politico report last year, Trump Jr. asked Hairston to serve as a liaison between sportsmen’s groups, Interior Secretary Ryan Zinke and the White House.
Prominent cases of NFL players with CTE
Prominent cases of NFL players with CTE
San Diego Chargers Junior Seau during a game against the New York Jets at the Qualcomm Stadium Sunday November 3, 2002, in San Diego, CA. (Photo by Matt A. Brown/Icon Sportswire via Getty Images)
Frank Gifford provides the classic throwing motion in his University of Southern California Trojans uniform. Following his college days, Gifford went on to star for the NFL's New York Giants, then worked as a broadcaster for CBS and ABC's Monday Night Football. (University of Southern California/Collegiate Images via Getty Images)
CLEVELAND - OCTOBER 9: Quarterback Ken Stabler #12 of the Oakland Raiders on the ground after taking a hit during a game against the Cleveland Browns at Municipal Stadium on October 9, 1977 in Cleveland, Ohio. The Raiders defeated the Browns 26-10. (Photo by George Gojkovich/Getty Images)
SAN FRANCISCO, CA - OCTOBER 14: Defensive back Tyler Sash #39 of the New York Giants on the sidelines against the San Francisco 49ers during the third quarter at Candlestick Park on October 14, 2012 in San Francisco, California. The New York Giants defeated the San Francisco 49ers 26-3. Photo by Jason O. Watson/Getty Images)
Inside linebacker Jovan Belcher #59 of the Kansas City Chiefs watches from the sidelines during his final game against the Denver Broncos at Arrowhead Stadium on November 25, 2012 in Kansas City, Missouri. (Photo by Jamie Squire/Getty Images)
PITTSBURGH - SEPTEMBER 13: Offensive lineman Terry Long #74 of the Pittsburgh Steelers talks with offensive line coach Hal Hunter (R) on the sideline during a game against the San Francisco 49ers at Three Rivers Stadium on September 13, 1987 in Pittsburgh, Pennsylvania. (Photo by George Gojkovich/Getty Images)
Mike Webster #52 of Pittsburgh Steelers looks on during a game circa 1987 at Three Rivers Stadium in Pittsburgh, Pennsylvania. Webster played for the Steelers from 1974-88. (Photo by George Gojkovich/Sporting News via Getty Images)
Quarterback Earl Morrall #15 of the Miami Dolphins looks on from the sidelines against the New York Jets during an NFL football game at The Orange Bowl November 19, 1972 in Miami, Florida. Morrall played for the Dolphins from 1972-76. (Photo by Focus on Sport/Getty Images)
Defensive tackle Shane Dronett #75 of the Atlanta Falcons in action during the game against the New York Jets at the Giants Stadium in East Rutherford, New Jersey. The Jets defeated the Falcons 28-3. Mandatory Credit: Todd Warshaw /Allsport
Dave Duerson #22 of the Chicago Bears looks on during a game in the 1985 season. (Photo by Jonathan Daniel/Getty Images)
WASHINGTON, D.C. - DECEMBER 31: Guard John Wilbur #60 of the Washington Redskins rests on the sideline against the Dallas Cowboys at RFK Stadium in the 1972 NFC Championship Game on December 31, 1972 in Washington, D.C. The Redskins defeated the Cowboys 26-3. (Photo by Nate Fine/Getty Images)
PHILADELPHIA, PA - DECEMBER 10: Defensive back Andre Waters #20 of the Philadelphia Eagles looks on from the sideline during a game against the Dallas Cowboys at Veterans Stadium on December 10, 1989. in Philadelphia, Pennsylvania. The Eagles defeated the Cowboys 20-10. (Photo by George Gojkovich/Getty Images)
EAST RUTHERFORD, NJ - SEPTEMBER 21: New York Jets players tackle New England Patriots player Mosi Tatupu during a game at The Meadowlands Sports Complex in East Rutherford, N.J. on Sept. 21, 1987. The game was the last game before a strike in the NFL. (Photo by Bill Greene/The Boston Globe via Getty Images)
PITTSBURGH - AUGUST 31: Offensive lineman Justin Strzelczyk #73 of the Pittsburgh Steelers on the sideline during a game against the Dallas Cowboys at Three Rivers Stadium on August 31, 1997 in Pittsburgh, Pennsylvania. (Photo by George Gojkovich/Getty Images)
CIRCA 1968: Defensive Tackle Bubba Smith #78 of the Baltimore Colts is seen watching the action from the bench circa 1968 during an NFL football game. Smith played for the Colts from 1967-71. (Photo by Focus on Sport/Getty Images)
LOS ANGELES - AUGUST 1: Running back Ollie Matson #33 of the Los Angeles Rams poses for a publicity photo during training camp at Chapman Colleg on August 1, 1961 in Orange, California. (Photo by Vic Stein /Getty Images)
FILE: Baltimore Colts HOFer John Mackey during a game against the Pittsburgh Steelers. (Photo by Cliff Welch/Icon Sportswire via Getty Images)
BALTIMORE - OCTOBER 11: Chris Henry #15 of the Cincinnati Bengals runs with the ball against the Baltimore Ravens at M&T Bank Stadium on October 11, 2009 in Baltimore, Maryland. The Bengals defeated the Ravens 17-14. (Photo by Rob Tringali/Sportschrome/Getty Images)
CHICAGO, IL - OCTOBER 15: John Grimsley #59 of the Houston Oilers lines up during a football game against the Chicago Bears on October 15, 1989 at Soldier Field in Chicago, Illinois. The Oilers won 33-28. (Photo by Mitchell Layton/Getty Images)
SAN DIEGO, CA - SEPTEMBER 24: Defensive end Pete Duranko of the Denver Broncos watches from the sideline against the San Diego Chargers at San Diego Stadium on September 24, 1972 in San Diego, California. The Chargers defeated the Broncos 37-14. (Photo by James Flores/Getty Images)