Livingston defender Declan Gallagher was sentenced to three years imprisonment last year along with co-accused hairdresser Anthony Murray for the serious assault, but was released on bail pending his appeal.
Murray was also liberated ahead of the hearing.
The Scottish Championship side announced it had decided to re-sign the player ahead of his legal challenge being heard.
But Gallagher, 24, and Murray, 30, were returned to prison yesterday after three judges at the Court of Criminal Appeal in Edinburgh decided there had been no misdirection by Sheriff
Douglas Brown at their earlier trial at Hamilton Sheriff Court.
Gallagher, of Heron Rise, Dundee, and Murray, of Ashley Place, Blantyre, were convicted of assaulting Steven Findlay to his severe injury and to the danger of his life in an attack at the Parkville Hotel, in the Lanarkshire town’s Glasgow Road on April 21, 2013.
While acting with others, they repeatedly punched and kicked him on the head and body, and knocked him to the ground and struck him on the head with a baseball bat or similar implement.
The victim suffered head wounds, a fractured skull and brain haemorrhage. A paramedic kept talking to him to try to keep him conscious as he was taken to hospital after the assault.
The sheriff said: “I considered that the sentence of three years which I imposed was at the lower end of the scale for a crime of such gravity, being a vicious assault with a weapon causing danger to life.”
But Gordon Jackson QC, who appeared for both men to challenge their convictions, argued that the sheriff had erred in responding to a question from jurors.
Advocate depute Ashley Edwards said there had been no misdirection and told appeal judges: “There was no confusion in his directions.”
Lady Smith, who heard the appeal with Lord Drummond Young and Lady Clark of Calton, said the jury had posed a question over whether they could delete the phrase “baseball bat or similar implement” from the charge.
The sheriff held a discussion with the prosecutor and defence before addressing jurors. Mr Jackson submitted that his subsequent
directions amounted to a misdirection, particularly as he had indicated they could leave the word “implement” and delete “baseball bat or similar”.
He argued that there was a real possibility that the jury did not do what was in their contemplation because of the sheriff’s direction.
But Lady Smith said they were not satisfied that what had occurred amounted to a misdirection by the trial sheriff.
The senior judge said: “These appeals are accordingly refused.”