The Bayern Munich striker was expected to be amongst the leading scorers having been top scorer in Germany's Bundesliga with 24 goals, as well as hitting 15 goals for Italy.
However, Toni suffered a nightmare tournament, notably against France where he missed a number of good opportunities to score. However, he refused to take the blame for Italy's quarter-final exit.
"In Italy I received a lot of criticism after the European Championships, because obviously people expected goals and I didn't score any," he told La Gazzetta dello Sport.
"I thought I played well, but clearly it is easier to criticise me, someone who plays abroad, than someone who plays in Italy."
Bayern return to the UEFA Champions League after reaching last season's UEFA Cup semi-finals, but the ex-Fiorentina and Palermo hit man realises that the squad will need to be expanded if they are to be successful.
"If the club wants to compete in the Champions League and win the championship, it has to invest to have a squad larger than 15 or 16 strong players.
"The team needs to strengthen all areas, because realistically, on paper there are stronger teams than us in the Champions League."