Teammates had to separate the pair at full-time as emotions spilt over.
But Blue Birds boss Neil Harris played down the incident, labelling it as merely “passion”.
“In the heat of the moment, I’ve got no problem with that,” Harris said. “I’ve got no complaint at all about passion. They came into the dressing room cuddling.”
The loss to Forest was the first at home for Harris since taking charge in November, leaving the club six points off the play-offs down in 10th.
And Harris also took time to bemoan the decision from referee Steve Martin to not award his side a penalty.
“When a referee gets it wrong he goes home and he is allr ight. For us that is two games in a row here that the referee’s decisions have cost us,” Harris said.
“It was a big moment in the game on the stroke of half-time. Who knows what might have happened if we’d got the penalty and scored it?
“He (Matty Cash) got nowhere near the ball. The ball was the wrong side of the player making the attempt. He kicked Josh (Murphy) and he had no option other than to go over given the speed he was running at, so it’s a penalty for me.
“They were a team we thought we could catch, but that’s going to be difficult now with games running out.
“We have to keep pushing to get back in contention for the play-offs. We need to turn the draws into wins because games are running out.
“We’ve got another huge game at the weekend against Brentford and while there is an opportunity we have just got to keep pushing.”