Coventry City have lodged an appeal to the Football Association for Gary McSheffrey's red card against Boavista to be rescinded.
The striker was sent off in the 27th minute for alleged violent conduct, although manager Micky Adams believes there is sufficient evidence for the dismissal to be revoked.
"We've reviewed the video and I've got no doubt at all that the red card should be rescinded," Adams said.
"We believe that the referee was facing the wrong way to see any incident and, further to this, we feel there wasn't an incident at all."
As the red card was in a non-competitive fixture, any three-match ban would not commence until a fortnight after the game, meaning that McSheffery will be eligible to play in City's first two games of the season, against Sunder-land on August 6 and Southampton on August 9. The appeal will go before a disciplinary commission next week.
Adams has failed in his bid to bring Lee Croft to the Ricoh Arena after the winger opted to join Norwich City, but he is thought to be interested in Sunderland striker Kevin Kyle.