Garlett came forward on Monday about his involvement in an incident outside a city bar at 5am on Sunday, which resulted in the arrest of four men.
It emerged only yesterday that Robinson was also there.
He has been fined $5000, the maximum available under player rules. The eye socket injury means his season is in effect over.
Robinson said coming clean about his involvement early would have been the best thing for the club, conceding he had jeopardised his future with the Blues.
"I'd like to apologise to the club and the players and supporters for withholding the truth of what happened on Sunday morning," Robinson said on Friday.
"Putting yourself in situations like that outside of a [nightclub] where people are lingering around and kind of drunk … I'll learn from that and put things in place where I can be home at a reasonable hour.
"We were in negotiations so I'll go back to the club next week and we'll talk about that.
"I've got four weeks to put my best foot forward and prove to the club why I should be here."
Robinson said he got involved in a scuffle to push away Garlett's attackers and during that time he was "king hit a couple of times".
He said he didn't tell the club immediately because he was worried about the pair's circumstances and the potential fallout.
"Once we realised we were in the wrong spot at the wrong time we decided to get out of there," he said.
"In doing that I went straight home and spoke to 'Jeffy' the next day.
"I wasn't too clear on what happened to Jeff."
Carlton football operations manager Andrew McKay said while the players were the victims, the fact they were out so late and covered up Robinson's involvement was very disappointing.
"Mitch presented to the club on Monday with a sore eye and he went and had some scans, and we asked him why and he said he'd been sparring," McKay said.
"We found that not to be the case.
"We don't want our players out at that time of the morning, especially when one (Garlett) is trying to get back into the team and one (Robinson) is suspended.
"We're very disappointed that they weren't truthful with us."
Both players are off contract at the end of the season but McKay wouldn't be drawn on their future.
It's not the first time Robinson has been involved in an off-field incident. He was involved in an altercation at the Big Day Out music festival in 2013, resulting in him being ordered to perform two months community service and donate $1000 to charity.
"We don't want to discuss anyone's future at the club.
"We haven't sat down as a player management group and discussed this at all."
Coach Mick Malthouse went through a similar situation when he was at the helm of Collingwood, when Heath Shaw and Alan Didak lied about a car crash.
"Mick’s feeling disappointed and the same as me, frustrated about the whole deal," McKay said.
"We're trying to build a culture here that's strong and we need to have everyone on board to do that."
Garlett was set to be recalled from the VFL for the Blues’ clash tomorrow with Gold Coast at Etihad Stadium before Malthouse ruled him out.
Robinson had just completed a two-game suspension for rough conduct from the round 18 game against North Melbourne.
