Police are still investigating the incident after Chelsea fans were filmed shouting racist abuse towards the England international at Stamford Bridge in December.
Berrarda said: "Chelsea have done a very good job at demonstrating that it is something that won't be tolerated anywhere in football. In that sense we were very aligned.
"There was a really good collaboration between the two clubs to tackle this issue.
"It was a terrible situation to be in. We as a club offer all type of support as a player.
"Both from a moral support ensuring that Raheem (Sterling) felt he had the backing of anybody at the club and we also have worked together with different stakeholders to ensure we provide as much information so they can carry on their investigation."