Former Jacksonville Jaguars linebacker Russell Allen has revealed that he suffered a stroke during his side's defeat to the Buffalo Bills in December.

The incident occurred early in the third quarter when Allen collided with Bills centre Eric Wood, but he initially thought that he was suffering from concussion and entered the field of play again later in the match despite experiencing double vision on the sidelines.

The 27-year-old informed team doctors about the symptoms when a headache failed to subside, and tests showed that he had suffered a stroke and would not be able to play the sport again.

"It was strange because [the hit on Wood] was so routine. We hit, I got off the block, no big deal," Allen told TheMMQB.com.

"I felt something flash - like they say when you get your bell rung. I didn't lose consciousness. I walked back to the huddle and finished the drive."

Allen joined the Jaguars as an undrafted free agent in 2009, recording 452 tackles, two sacks and three fumble recoveries in his career.