"I know the players are playing for me because I only need to see what they do on the pitch and the amount of acres they cover," said Calderwood.
"What I see excites me and lifts me. They believe they are good enough to stay in this division and we only find that out at the end of the season.
"The players have always had belief and they're not scared of anything but we've made some simple mistakes again today which have cost us points - and we've done that in the past. We need to eradicate them."
Coventry boss Chris Coleman admitted the game could have gone either way.
"I could be sitting here celebrating a win but (Lee) Camp has made a fantastic save (from Michael Mifsud in the 89th minute)," he said.
"Having said that, I could be disappointed that we have got nothing from the game.
"At training yesterday, we only had 12 senior players fit so it's been difficult. I am hoping the next transfer window is going to be fruitful for us."