Darren Ferguson said he was the most angry he had been since Doncaster Rovers' previous trip to Colchester United following his side's first half performance on Good Friday.
In their first outing since securing promotion, Rovers were decidedly lethargic in a first period in which they fell behind.
But Mathieu Baudry headed home an equaliser in first half stoppage time, sparking a much-improved performance after the break and they arguably should have won the game.
Those pleased with the response in the second half, Ferguson could not hide his frustration over Rovers' start to the game.
"That was the most angry I've been all season - probably since we came here last year," he said after the game,
"We were miles off it.
"It just wasn't acceptable. I'm not having that, I don't care whether we've been promoted or not. I'm not interested."
Ferguson added: "I'm disappointed we didn't win it in the end. We were the team in the ascendancy.
"Second half, I thought we were very good but the first half we were very, very poor. As poor as we've been for a long time.
"That was very disappointing.
"But the second half we showed much more what we're about and we should have won it.
"You have to give credit to Colchester. We knew they'd start the game lively. We knew they'd press.
"We were just second to everything.
"If we play in the first how we did in the second, we would have won the game comfortably."
Ferguson revealed Baudry's first half performance was the reason he was withdrawn at half time, and did not mince his words.
"He was rubbish," he said.
"He did well to get the goal but he was miles away from it today.
"It wasn't good enough."
James Coppinger, Ian Lawlor and Andy Williams all missed the game with groin, chest and calf injuries respectively.
READ MORE: On-the-whistle report - Colchester United 1 Doncaster Rovers 1