Port Vale had David Worrall sent off after the final whistle as they were beaten 2-1 at Scunthorpe.
He was shown red along with the home side's Matthew Lund following an off the ball altercation.
The winger is now facing a three match ban unless the club decides to appeal and are successful.
Manager John Askey named an unchanged starting line-up for the game.
And they went in front after half an hour through Jake Taylor.
The midfielder is now the club's joint leading scorer along with Richie Bennett.
But the hosts hit back seven minutes later through Kevin van Veen.
Scunthorpe then netted what turned out to be the winner six minutes after the restart through Kgosi Ntlhe.
The result leaves the Vale in 9th place just two points off the play-off places.
The Valiants are next in action on Saturday when they make the trip to fellow League Two outfit Cheltenham in the second round of the FA Cup.