Stressed Lionel Messi Barcelona enchanting the need to exert maximum effort as possible at home to Manchester City today in the framework of the second leg round of 16 of the Champions League at the " Camp Nou " .
 The Argentine international superstar in remarks published by the newspaper " Metro " , said: "We have to show respect for all City today , because it is a great team , and holders and amazing potential and players at the highest level in all the centers ."
 He added: " City is full of team skills , and players from different model , and we know very well what they can do , especially in the big confrontations , our mission is not over the purpose , so we have to be better in our case ."
 He continued: " Manchester City has received very good news for the return of its star Argentine Sergio Aguero to join him after recovering from injury , I know very well the capabilities of this player ."
 He warned of the gravity Messi Aguero said: " Argentine striker my friend and I know its gravity well , and its ability to form a crisis for opposing defenses in the biggest difference , so we have to respect it as much as the well- characterized by the seriousness ."
 It is noteworthy that Aguero has been absent from the first leg injury in the game figs ended two straight on the Etihad Stadium .