Portugal midfielder Bruno Fernandes says it was a dream to play with Cristiano Ronaldo at Manchester United, but "nothing lasts forever".

The striker parted ways with the Premier League club by mutual consent on Tuesday and is searching for a new club, with Portugal due to kick off their World Cup campaign against Ghana on Thursday.

Along with Ronaldo's departure, Manchester United also issued a bulletin saying the club could be sold by owners the Glazer family.

Ronaldo, 37, had spoken in a controversial interview last week, where he lashed out at coach Erik ten Hag and the club itself, provoking his eventual departure.

"I don't feel uncomfortable, I don't have to pick a side. It was a dream come true to play with Cristiano at United but nothing lasts forever," Fernandes told a press conference Wednesday.

"It is his career and we have to respect such decisions, every decision has to be respected regardless of whether you agree or not.

"We as players, but also as parents, brothers, we know it might be difficult to take some decisions but these decisions have to be for the wellness of ourselves and our families."

Ghana coach Otto Addo thinks that Portugal will not be affected by Ronaldo's split from Manchester United.

"I don't care, it's not our problem and I don't think it's a big problem," Addo told a press conference Wednesday.

"Everybody wants to win and we're at World Cup level, I don't think this can disrupt anybody."

Black Stars captain Andre Ayew agreed with his coach and said Euro 2016 winners Portugal would be favourites for the clash at Stadium 974 in Doha.

"As my boss said it's not really our problem what's happening in the Portuguese team, they are great professionals, playing for top teams, they will be ready for the World Cup," said Ayew, who plays for Qatari club Al-Sadd.

"Portugal are the ones who are favourites on paper, we have to show on the field, that on paper is not what will happen on the pitch."