Just two months after becoming European champions, Manchester United will arrive in South Africa on Friday for their pre-season tour resembling a club in crisis rather than a team at the peaks of its powers.

The UEFA Champions League penalty shoot-out victory over Chelsea on a rain-soaked night in Moscow's Luzhniki Stadium in May was a true high-point for United, but the turbulence that has followed continues to reverberate throughout Sir Alex Ferguson's squad.

Cristiano Ronaldo's open desire to leave the Premier League champions for Real Madrid, the departure of Ferguson's trusted assistant, former South Africa coach Carlos Queiroz, and the failure so far to add to last season's squad, ensure that United will launch their tour, against Kaizer Chiefs in Cape Town on Saturday, with real uncertainty surrounding the club.

When they last visited South Africa two years ago, United were racked by similar problems. Ruud van Nistelrooy was on the verge of his transfer to Real Madrid and Ronaldo, once again, was questioning his future after his infamous World Cup bust-up with Wayne Rooney during Portugal's quarter-final clash against England.

Yet Ferguson and his team emerged as champions that season and the South Africa tour was viewed as a turning point, with Patrice Evra proving his worth and Ole-Gunnar Solskjaer re-emerging after two years of injury misery.

Buoyant mood
So while there remain question marks over Ronaldo's future, the prospects of signing Spurs striker Dimitar Berbatov, and the identity of Queiroz's successor, United go into their three-game tour in buoyant mood, according to midfielder Michael Carrick.

"The season has come round pretty quickly, but it is the longest I have had off for a number of years. It was nice to have the break, but I have been ready to come back," Carrick said.

"We start from square one and have to do it all over again. It will be a long season once more but we are up for the challenge.

"We won our first pre-season game at Aberdeen last Saturday, but it was all about the fitness and getting the performance that little bit sharper.

"Now we move on to the next game and we will be ready for South Africa. Obviously we are nowhere near our peak but that is what pre-season games are for. We have trained hard, but the games are where you find your edge."

Although Ronaldo will be absent as he recovers from ankle surgery, England star Carrick will be joined by the likes of Rooney, Carlos Tevez, Rio Ferdinand and Ryan Giggs on the tour as United send a strong squad ahead of the new campaign.

Fit-again captain Gary Neville also travels after 18 months of injury problems and he is likely to figure as United play games in Cape Town, Durban and Pretoria, before flying to Nigeria for a friendly against Premier League rivals Portsmouth in Abuja.

On their return to England, United will stage Old Trafford friendlies against Espanyol and Juventus, but manager Ferguson expects the South Africa tour to prove priceless in terms of readying his players for the season ahead.

Ferguson said: "The games in South Africa aren't easy games. It's a good, competitive level, so that should bring us on a good deal.

"I think by the time we get to the start of the season we'll be really ready."