GARETH Ainsworth admitted Wanderers' exit from the Johnstone's Paint Trophy hinged on his side being temporarily down to ten men with Matt Bloomfield off the field injured.
The midfielder was forced off to get stitches in a cut head, leaving his team mates to play a man light while he received treatment.
By the time he came back onto the pitch sporting a huge bandage Coventry City had taken advantage of the extra space left by his absence to score what proved to be the only goal of the game.
But Ainsworth said he didn't want to make an unnecessary substitution, saying Bloomfield's contribution to the game after his reintroduction justified the decision not to make the change.
The Blues boss said: "Blooms has gone off with a head injury for five or six minutes and that's cost us.
"A team like Coventry thrive on the midfield. We knew that and we stopped that with our midfield.
"We lost one of our midfielders for five or six minutes and they took advantage. It's one of those things. People with hindsight will say, 'Why didn't you replace the midfielder?' I thought Blooms was having a cracking game.
"In the last 20 minutes we were creating chance after chance, forcing corners and he was at the heart of everything."