Most Manchester United fans were overjoyed when Alexis Sanchez put pen to paper at Old Trafford.

But Marcos Rojo had a completely different reaction, saying: 'Oh, f****** hell no', when the former Arsenal man went from rival to team-mate.

The central defender had been fiercely competitive with the Chilean at both club and international level, admitting that they didn't have a good relationship.

Marcos Rojo (right) hasn't always had a good relationship with Alexis Sanchez (left)

The pair were fierce rivals and Rojo admitted to giving the former Arsenal man a good kicking

'Alexis is a great player, but we didn't used to get on out on the pitch,' he told TyC Sports.

'Every time we came up against one another, whether in internationals or when United played Arsenal, I would give him a good kicking — and he did the same to me.

'On top of that I used to insult him, and he would reply in kind.'

And given their history, Rojo admitted his reaction to the news of Sanchez's impending arrival was far more negative than most.

Rojo said that his initial reaction to Sanchez joining Manchester United was: 'Oh, f****** hell no'

'So when I learned that he was going to join United I said Oh, f****** hell, no, now this guy's going to be here,' he said.

The 27-year-old Argentina international also revealed that Jose Mourinho knew it would be a sore spot and made a point of teasing him about it.

Rojo went on: 'He told me: "We're going to sign Alexis. I don't want you smashing him up in training tomorrow".

'He burst out laughing.'