The 26-year-old shoved the ball boy in stoppage time at the Parc des Princes, sending him into a chair and triggering a confrontation between players.
"I want to apologise to the ball boy," Neto told TNT Sports. "I have already spoken to him."
"We were losing and in the emotion of the game I wanted to get the ball fast and I gave him a little push.
"I'm not like this. It was in the heat of the moment and I want to apologise. I gave him my shirt. I'm really sorry about it - I feel I have to apologise to him ... He could see what had happened and was happy with the situation."
Head coach Liam Rosenior also apologised for the incident.
"If there was anything from our side that was wrong or out of order, I apologise on behalf of the club," he said.
Luis Enrique's side twice went ahead through Bradley Barcola and Ousmane Dembele but were pegged back each time by Malo Gusto and Enzo Fernandez, before Vitinha and Khvicha Kvaratskhelia, with a double, netted three late goals to put the hosts in control of the tie.
The visitors' disappointment was evident at full-time, with goalkeeper Filip Jorgensen attempting to head straight down the tunnel before Robert Sanchez urged him back to applaud the travelling supporters.
Chelsea will play Newcastle United on Saturday in the Premier League before hosting PSG on Tuesday in the second leg of the last-16 tie in the Champions League.
