"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 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 tournament.