Messi steps up as Argentina's chief creative force

(Reuters) - When Lionel Messi plays for Barcelona he is the goalscorer supreme but when he represents Argentina the responsibility carried by FIFA's world player of the year is far greater.

After Monday's emphatic 3-0 win over Costa Rica in the Copa America in which Messi ran the show, the real tests lie ahead in the knockout phase of the tournament.

Hosts Argentina, second in Group A, will learn later on Tuesday who they will meet in the quarter-finals on Saturday when one of three teams in Group C will emerge, also in second place, from among Uruguay, Peru and Chile.

"We had a change of mentality and game above all, we were more mobile, Messi brilliant and I'm satisfied with the commitment and play of the team which is what we're looking for," coach Sergio Batista said.

Batista is aware Costa Rica were not the same kind of test as Colombia who should have beaten Argentina in their second group match which ended goalless with their own fans booing Messi and the team.

But Batista told a news conference: "We have players to face any national team.

"We did it against Costa Rica who until a short while ago were (considered) a fantastic team who played very well (in a 2-0 win over Bolivia) but you also have to look at Argentina, because what they did was very good."

Critics said Batista had lost his way with his team choices, including three holding midfielders, when he preached a game similar to that of European champions Barcelona.

They might have lost his first competitive match in charge when Argentina opened Group A with a 1-1 draw against Bolivia in La Plata on July 1.

Messi has gone 15 competitive matches for his country without scoring a goal, a remarkable statistic for a player who has netted 180 for Barcelona.

This did not matter on Monday night when Messi laid on a string of chances, threading perfect passes through a packed defence to the forwards and Argentina could have ended with a bigger winning margin.

Perhaps good results and performances in friendlies blinded Batista to what might happen against well organised defences looking to snatch points on the counter-attack.

"Today we changed our tactics a bit giving Lionel the right side (of the pitch)," said Batista referring to Messi's preferred flank for Barcelona where he can start diagonal runs at and across the defence.

"We bet on three forwards and it worked, we got our organisation sorted and we played the game we want."