The cornerback passed away on Monday (30.05.22) after being involved in a road traffic accident in the early hours of the morning and the sad news was confirmed by his agent in a statement to the Fort Worth Star-Telegram.
His representative Brian Overstreet said: "We are asking prayers for the family and privacy at this most difficult time."
The publication reports a female passenger also lost her life in the crash, which is now under investigation.
No more details about the crash have been released.
Jeff's former teammate, Philadelphia Eagles star Jalen Reagor, mourned his loss on Twitter, writing: "Lost my Brother, my best friend, my right hand man ... ain’t too much more I can take. R.I.P Jeff Gladney, brother watch over me please."
Jalen played college football alongside Jeff at Texas Christian University (TCU) in Fort Worth. Jeff was later a first-round pick for the Minnesota Vikings during the 2020 NFL draft.
A statement released by the NFL added: "The NFL family mourns the tragic loss of Jeff Gladney and we extend our deepest condolences to his family and loved ones."
TCU athletic director Jeremiah Donati said: "Our TCU Athletics family, and especially our football program, was very devastated to learn of the passing of Jeff Gladney.
"After earning his degree and continuing his playing career in the NFL, Jeff maintained his close ties to TCU. He loved everything about his alma mater. He was a frequent visitor to campus and was at our spring practices and spring game this year, proudly joined by his young son."
After leaving the Vikings, Jeff went ton to play for the Arizona Cardinals, who added in a statement: "We are devastated to learn of Jeff Gladney's passing. Our hearts go out to his family, friends and all who are mourning this tremendous loss."
Jeff played played in 16 games for the Vikings but sat out the 2021 season as he battled a felony assault charge in a domestic violence case.
He was found not guilty back in March and went on to sign a new two-year deal wth the Cardinals in May.