Wales manager John Toshack believes Manchester United hold the upper hand heading into their Champions League semi-final against Barcelona whether Lionel Messi is up against them or not.
However, the former Real Madrid and Real Sociedad boss insists the tie could yet go either way, with the chance of injuries and suspensions possibly having a big part to play over the two legs.
The fitness of Messi is one of the main talking points ahead of Wednesday's first leg at the Nou Camp, with the Argentina star having made just two substitute appearances for Barca since returning from more than a month out with a hamstring injury.
It remains to be seen whether the 20-year-old will start against United, but whatever happens Toshack feels the English champions will still hold the edge against the out-of-sorts Catalan side.
Toshack told Spanish newspaper El Mundo Deportivo: 'Manchester United are favourites with or without Messi, but if suddenly they lose a player like (Rio) Ferdinand or (Nemanja) Vidic and Messi is on the pitch, the tie could turn around 180 degrees.
'Now I see it being Manchester United and Liverpool, but just the same it could be Barca-Chelsea. Injuries and suspensions could play a big part yet.
'(Also) the coaches must be aware of the influence that a goal conceded at home could have on the fans and on the players. When you reach this level, it is almost like a game of chess. You need to consider all the details.'
United are the more in-form of the two sides, with Sir Alex Ferguson's men having won 10 of their last 13 competitive matches, while Barca have picked up just four victories from the same amount of games.
Barcelona boss Frank Rijkaard's performance will come under review at the end of the season but Toshack believes being underdogs in their semi-final could actually suit Barcelona.
'United are favourites but maybe this is a good thing for Barca,' he said.
'Ferguson is the first person who would not want to go in as favourites, but what what happens is that if Rijkaard, (Rafael) Benitez or (Avram) Grant do not win the European Cup, then they could be out on the streets. Only Ferguson will continue whatever happens. What a demand! You have to win the the European Cup.
'And the Champions League is even more difficult than in my time. It is terrible to say that if you do not win the Champions League you have failed, but it is like that now.'
Toshack was also asked about the possibility of Jose Mourinho taking over at Barcelona this summer.
There has been speculation that this will be Rijkaard's last season the Nou Camp, and the former Chelsea boss is one of the names being touted as a possible replacement for the under-pressure Dutchman.
'I cannot talk about this with respect to the coach who is at Barca. They are also talking about Rijkaard going to Chelsea,' said Toshack.
'The European Cup and the two leagues that he (Mourinho) won with Porto and the two leagues that he won with Chelsea are there for all to see. What more can you say?'