Rovers’ standing in sixth spot was weakened with Tuesday night’s 2-1 defeat to struggling Accrington Stanley.
The poor performance, particularly in the first half, drew grumbles from the stands at the Keepmoat and the players were booed off at the break.
And afterwards McCann urged everyone to stick together as they look to pick up the two wins that will likely secure a play-off place.
“We haven’t got time to dwell,” McCann said.
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“We have to move on and we have to stick together.
“We’ve come this far and the last thing we want to do now is throw the toys out of the pram.
“That includes everyone – the fans and everyone. We need to stick together.
“We are not going to do this if there is a split in the camp.
“There won’t be one in my changing room.
“The boys are fully focused on the next game and that is Oxford.
“It’s a game that we have to go and win.”
On the reaction of supporters at the Keepmoat, McCann said he could understand their frustrations, particularly with a first half performance which saw Rovers fall two goals down.
“I think it started before Accrington scored,” he said. “There were a few boos and people shouting on.
“We’ve got to remember that we were 15th in the league at this stage last season, fighting to stay in the league.
“We’ve turned a corner. We're two games away from getting into the play-offs here.
“The group needs to stick together and the fans need to stay behind us.
“The majority of them have. They’ve been outstanding for us this season.
“When they’re behind us they really drive the group.
“I can see their frustrations with the first half performance.
“But the boys are hurting and we need to pick them back up.”