MK Dons manager Karl Robinson is set to appeal against the opening day red card for midfielder Stephen Gleeson.
The dismissal took the gloss off his side's 5-3 penalty shootout win in the Capital One Cup first round tie at Cheltenham after the teams drew 1-1 at the end of extra-time.
Dean Bowditch had handed the visitors the lead deep in first half injury-time, with Kaid Mohamed hitting a stunning 30-yard equaliser on 58 minutes. But the sending off of Republic of Ireland international Gleeson just before the Dons went in front had Robinson reaching for the match video.
"We all know it was a very, very good tackle," the Dons boss said. "He did not have his body off the floor and he did not have his studs showing. The disappointing thing for me is that the same player who was lying on the floor is running around within 30 seconds and 10 minutes before that he got booked for diving.
"It was a difficult one for me to accept - I didn't even think it was a free-kick. The referee was very respectful and he appreciates that I will try and appeal that one."
Dons defender Shaun Williams also limped off before the break to make it a frustrating start to the season for Robinson, who added: "Shaun Williams is a big loss to us. We had 75 minutes to go with arguably two of our better players missing. To lose one to injury and another to a silly sending off is hard to take. But we have tried to bring players in."