Luke Knox, a Florida International football player and younger brother of Buffalo Bills star Dawson Knox, has died suddenly at 22.

School officials and Bills head coach Sean McDermott have confirmed the passing. A specific cause of death has not been revealed, but police do not suspect foul play.

‘Our hearts go out to Dawson and his family during this time,’ McDermott told reporters at Bills training camp at St. John Fisher in Pittsford, New York. ‘We’re right there with him and supporting him and his family — and just tragic news that I woke up to this morning.’

Luke originally enrolled at Ole Miss as a linebacker and tight end, but had since transferred to FIU, where he was hoping to compete for a linebacker spot. He did get to play two seasons with Dawson at ole Miss before the older sibling was drafted by the Bills as a tight end in the 2019 NFL Draft.

Mike MacIntyre, FIU’s head coach who also previously worked with Luke as Ole Miss’ defensive coordinator, also released a statement.

‘Luke’s family is special to me and they will continually be in my heart and my prayers during this difficult time,’ MacIntyre said. ‘On behalf of the entire FIU football family, I extend sincere condolences to Luke’s family and all who love him.’

Ole Miss coach Lane Kiffin also released a statement on Thursday: ‘I am very grateful for my personal relationship and time spent with Luke,’ Kiffin said. ‘He was a tremendous teammate and an even better person who lifted up everyone around him.’

Luke and Dawson were close, and much of the former’s Instagram account was dedicated to the latter.

 So dang proud of you bro,’ Luke wrote on Instagram after Dawson was drafted in 2019. ‘Time to go get what’s yours!! Love you’

Dawson has not yet commented publicly about the tragedy, which occurred as he enters his fourth NFL season.

Luke started twice at linebacker for Ole Miss in 2019, but predominately played special teams.