Two Rangers fans were found guilty on Friday of assaulting former Celtic captain Neil Lennon.
A jury found Jeffrey Carrigan, 43, and David Whitelaw, 47, both of Knightswood in Glasgow, guilty by majority verdict at the city's Sheriff Court.
Part of the charge, that the attack was aggravated by religious prejudice, was dropped.
Lennon, 37, now a coach at the Glasgow club, needed hospital treatment after the attack in the early hours of September 1 last year.
Lennon had been out in the west end of Glasgow following his side's defeat to Old Firm rivals Rangers.
Carrigan and Whitelaw did not deny getting into a fight with Lennon, but claimed he was the initial aggressor.
They told the court the football coach started the fight after Carrigan asked him if he enjoyed the day's game. Sheriff Martin Jones jailed both men for two years each.
The pair were impassive as Sheriff Jones sentenced them.
He said: ''You have been convicted of a vicious, brutal and cowardly attack on an innocent member of the public who was making his way home in the early hours of the morning in Ashton Lane.
''That is an area popular with the public where they should feel safe and such an attack should be viewed seriously.''
Describing the attack on Lennon, he said: ''He was curled up trying to protect himself and offering no resistance. At some stage during this mindless attack the complainer was rendered unconscious.
''Once it ended you left the complainer lying on the ground and you made your escape. The complainer was fortunate that he did not receive more serious injuries, given the ferocity of the assault.''
The midfielder was born in Lurgan, Northern Ireland in 1971 and signed his first professional contract with Manchester City at the age of 18.
Having made his name at Leicester, where he won the League Cup in 1997 and 2000, he was signed by Celtic for £5.75million.
Lennon became part of the Celtic side that won five titles in seven seasons and reached the final of the UEFA Cup. He was made captain in 2005.
In 2007 he moved to Nottingham Forest, but after retiring from the game returned to Parkhead as first-team coach.
Lennon won 39 caps for Northern Ireland, but announced his shock retirement from international football in 2002 after claiming he had received death threats from an Ulster paramilitary group.