Neil Lennon claims Scott Brown's 'game-changing' dismissal in the 1-0 Champions League defeat by Barcelona at Parkhead was down to the overreaction of Neymar.
The home side were reduced to 10 men in the 58th minute when Brown was red carded by referee Stephane Lannoy after flicking a leg at the Barca forward following his original foul on the Brazilian star.
The Scottish champions were dealt another blow in the 76th minute when Cesc Fabregas headed the winner for the Catalans to leave the Scottish champions with no points from two Group H games.
Asked about his captain's red card, an unhappy Hoops boss said: "I think it is very soft. I have looked at it.
"If there was any contact, it was minimal. There was a lot more in a game that warranted heavier punishment.
"It was a game-changing decision. It is obviously very difficult playing Barcelona with 11 players and even more difficult with 10 but we played very well tonight.
"I don't think the initial tackle was a severe one. It is a physical game I don't think Neymar does himself any favours with the way he behaves at times.
"Our supporters are very respectful of great players. Iniesta walks off tonight to a standing ovation from the Celtic support. After the incident Neymar gets booed every time he touches the ball."
Asked if Brown should not have given the referee the opportunity to send him off, the former Celtic skipper said: "Possibly. It is a debatable point but again there wasn't much in it.
"There is no question it is a foul, but the reaction didn't merit it.