Guernsey FC manager Tony Vance says Jamie Dodd's sending off 'changed the game' as his side were beaten 4-2 at home by Corinthian Casuals.
Dodd was dismissed late in the first half after receiving two yellow cards.
"The sending off changed the game completely," Vance told BBC Guernsey.
"They got two soft goals, which is frustrating from because those goals they scored weren't because we were down to 10 men, it was just that they got a little bit of luck."
The defeat left Guernsey 18th in Isthmian league Division One South, with the Green Lions having lost four of their last six league matches.
"We move on, it was one of those days when you want to cross it out and move on," added Vance, whose side hit the bar and the post when they still had 11 men on the pitch.
"If you look at the first half it wasn't a great first half, but we probably shaded it with chances,.
"We didn't convert those and those are fine lines."