Chelsea goalkeeper Petr Cech has insisted the Blues can stop Barcelona\'s brilliant playmaker Lionel Messi when the clubs meet in the first leg of a Champions League semi-final here on Wednesday. The Argentinian is widely considered to be the outstanding player in a superb side that has been compared to the best ever seen in club football. But Cech is adamant Messi is \"only human\" and that European champions Barcelona can be beaten. \"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,\" Cech told his personal website on Tuesday. \"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 percent, we will be able to defend against him.\" Cech added: \"They (Barcelona) 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.\"