Ronaldo made his way back to Old Trafford last week after leaving Juventus.
During his first spell at Old Trafford, Ronaldo won the Champions League, Premier League titles, among others, including his first ballon d’Or.
Manchester United finished second behind rivals Manchester City last season and many believe Ronaldo’s arrival has seemingly boosted their chances of winning the Premier League this term.
But Barnes is not convinced, although he still believes it is a ‘good move’ for all parties.
“From the point of view of the prodigal son returning home it’s fantastic,” Barnes told BonusCodeBets via Metro.
“Of course, they’re not getting the Cristiano Ronaldo that they had or that Real Madrid had.
“But getting back a talisman and one of the greatest players that ever lived – not so much now because he’s 36 and on the way down – is a good signing for them.
“How will it affect the other players? They’ve seen one player leave already in Dan James and we’re probably not going to see as much of Marcus Rashford. Is that going to help the balance of the team?
“We don’t know, so we’ll have to wait and see. I think a lot of it had to do with nostalgia. Obviously, he’s a very good player, don’t get me wrong.
“If he’s going to cost as much as his salary costs and he’s going to help for a year, from a financial point of view they can afford it presumably.
“I don’t necessarily think it will make them any better in terms of winning the league,” he said.