O'hAilpin, 25, was banned indefinitely by the club after punching and kicking teammate Cameron Cloke during an intra-club match on Friday, February 6.
The Irishman is serving a four-match suspension after pleading guilty to striking and kicking charges.
While the episode caused an uproar and drew widespread condemnation at the time, Grigg said it was time to leave the unfortunate event in the past.
"He was back at training yesterday and it was good to have him back, but it's business as usual now," Grigg said on Wednesday.
"It was 10 days ago. We've all moved on, the club has dealt with it, and we'll move on from here."
O'hAilpin has been training with Carlton’s VFL affiliate the Northern Bullants and has been working with club sports psychologist Michael Martin since his undisciplined display.
Coach Brett Ratten said that the defender’s return to the main group hinged on a green light from the psychologist.
A contrite O'hAilpin was cleared to return early this week and faced his teammates on Tuesday.
"He had a few words to the boys and said that he was sorry," Grigg said.
"We've all moved on and we're looking forward to the game on Friday night … It’s all in the past now.
"I don't think there are any hard feelings. He's got to train hard and win back the respect of everyone and I'm sure he can do that."
Carlton begins its NAB Cup campaign against North Melbourne at Telstra Dome on Friday night.
Dream Team watch – Shaun Grigg is rated a $265,300 midfielder in Toyota AFL Dream Team 2009.
Setanta O'hAilpin is rated a $187,800 defender in Toyota AFL Dream Team 2009.
