Jos Luhukay explained that he brought off Sheffield Wednesday goalscorer Steven Fletcher in the defeat to Birmingham City because he believed the striker had lost his freshness.
Sections of the away support booed as Fletcher - who had given the Owls the lead at St Andrews - was brought off and replaced by Lucas Joao with 12 minutes to go.
Wednesday went on to lose the game 3-1 as Lukas Jutkiewicz and Che Adam netted on 80 and 84 minutes.
Afterwards Luhukay stood by his decision to withdraw Fletcher, who had arguably been the Owls' best performer in the game.
"Lucas Joao is our top scorer and I thought maybe Steven was not maybe fresh enough," he said.
"And Lucas is fresh when he comes off the bench and he can score in every typical moment for us.
"It is not that I was not happy with Steven, not at all.
"But I know also I can bring Lucas for a special moment. Even he had one or two moments to bring us back into the game.
"Today it was not the lucky day again for us."
Despite taking off Fletcher, Luhukay was full of praise for the performance of the Scotland international, who hit the post with a superb effort early in the game.
He said: "I think Steven was very positive.
"In the first minute he had a fantastic finish which went against the post and came outside. Two centimetres over and the ball goes in the goal.
"That would be 1-0 after one minute.
"Later Steven made us a good goal from a very good offensive transition.
"I think he was good in the game."