The Scot, who also played for Coventry City and Leeds, was left needing hospital treatment after the city centre attack last weekend.
He reportedly had three teeth knocked out and needed 12 stitches
A West Yorkshire Police spokesman said: “The male victim was stood outside a bar when a man approached him and punched him in the face causing injuries that required hospital treatment.
“A 32-year-old male was arrested last night (March 28) in connection with this incident.
“He has been released under investigation and enquiries remain ongoing.”
An appeal was made by former teammate Dominic Matteo for more information about the attacker.
He wrote on Facebook: “The attack was totally unprovoked and very vicious. Gary was hospitalised, lost three teeth and had plastic surgery on his lip which needed 12 stitches.”
He added that due to the severity of the injuries, he may have been wearing a “knuckleduster”.
McAllister was outside a bar on Call Lane, in Leeds city centre, when he was attacked at around 4am on Sunday.
He is believed to have been waiting for a taxi when he was struck.
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