Argentina forward Lionel Messi [ Images ] acknowledged he was not at his best for Diego Maradona's [ Images ] side in their World Cup qualifiers against Peru and Uruguay.

"I know that things did not go as well for me as I would have wished," Messi told reporters on his arrival back in Barcelona [ Images ] on Thursday after Argentina reached the 2010 finals.

"Many things have to change, we have to continue improving, growing as a team and prepare well for the World Cup," he added. "If we do things well we have a good chance because (we have) some very good players."

Argentina beat Peru 2-1 with a last-gasp goal on Saturday and then defeated Uruguay 1-0 in Montevideo on Wednesday to finish fourth and qualify for the South Africa [ Images ] tournament.