Petr Cech knows Chelsea will face a tough task trying to contain Lionel Messi when they face Barcelona on Wednesday night but has reminded his team-mates the Argentine is 'only human'.
The Blues are preparing to go up against the reigning European champions in the first leg of their UEFA Champions League semi-final at Stamford Bridge, with the Primera Liga giants favourites to progress and lift the trophy for a second successive year.
Goalkeeper Cech knows Barca, spearheaded by superstar forward Messi, will present a formidable challenge but insists Pep Guardiola's side are not unbeatable.
The Chelsea shot-stopper told his official website: "They are the biggest favourites of the Champions League, they are defending the trophy but anything can happen.
"We have two matches in which we can overturn the prognosis about favourites."
Cech added of top goal-scorer Messi, who has netted a record 41 times in La Liga this season: "As much as (Cristiano) Ronaldo is exceptional for Real, Messi is exceptional for Barcelona.
"Barcelona alone are an exceptional team with a fantastic generation of players and he is the most exceptional among the exceptional. He is even better than the rest.
"Messi in his current form is an enormous threat. He is for sure one of the best players in the world but, as I said before, no team is invincible.
"His ball technique is superb but, most importantly, he can react to how the game develops. At the last possible moment in any situation he can find the ideal solution. There are a lot of ways that Messi can finish an attack.
"On the other hand, he is also only human and if we perform to 100 per cent, we will be able to defend against him."
Cech has previously come up against Messi four times when Chelsea have played Barcelona but the Argentina ace is yet to put a goal past the keeper.
The Czech Republic international refuses to take all the credit for keeping the 24-year-old out, insisting his team-mates have played a crucial role in subduing him.
"Indeed, Messi has never scored against me so far," he added in France Football. "But I am not stupid enough to believe it is all because of me.
"If such a talented player could not score it is, above all, because I play in a team that has almost always been able to counter him.
"All alone against such a genius, I have no chance, even if I try to prepare for it."