They have been dubbed the "fantastic four". Sergio Aguero, Angel Di Maria, Gonzalo Higuain and Lionel Messi form Argentina's special strikeforce at this World Cup, but so far in Brazil only the Barcelona forward has lived up to the billing. And not even he can do it all alone.

Messi has proved decisive against both Bosnia-Herzegovina and Iran in his side's first two games, stepping up with stunning strikes to seal all three points in single-goal victories which had been expected to be much more straightforward. Despite Argentina's array of attacking talents, it is only Leo who is firing at the moment.

"Every time you have a player like Messi, there is of course overdependence," coach Alejandro Sabella said on Tuesday. "We try to reduce that but you have to depend on him. I guess this is normal pressure for a player and we try to reduce the pressure on him by playing together." Di Maria also admitted on Sunday that Argentina must offer more help to their captain after disappointing displays in their opening two matches. "We will all look to improve," the winger said. "It was important to get the six points (from the Bosnia and Iran games) to qualify for the next round. Now we will try to help Messi so that things are a little easier."

The Real Madrid man has so far been unable to replicate his excellent club form in this competition, but has seen his influence restricted by the lack of space in the opening two games.

Ahead of him, Aguero and Higuain have also flattered to deceive. Both injured pre-tournament, the two still lack rhythm and were substituted following ineffective performances against Iran on Saturday. The pair combined once in the first half, with the Manchester City striker seeing an effort saved by goalkeeper Alireza Haghighi, but did little else and Argentina's winner came when both were off the pitch.

Higuain had been left out of the opener and his half-time introduction helped Argentina improve against Bosnia, although that was more to do with the change in formation than his own performance. The Napoli striker did play his part, however, as he released the ball for Messi in a one-two which led to the forward's fantastic strike in the 2-1 win. More of the same is now needed as tougher tests than Bosnia and Iran await.

"El Pipa [Higuain] has been a little bit injured and didn't play the two games before the competition, while Kun [Aguero] has also had some injury problems," Di Maria said on Sunday. "It's difficult when you have injuries, it affects you, and it affects how you adapt alongside your team-mates."

The two strikers have trained normally this week, while Di Maria has fully recovered from the muscle fatigue he was suffering after the opener versus Bosnia. So against Nigeria on Wednesday, the trio have another chance to show what they can do ahead of the group stages, when they will all be expected to deliver. And on the day after Messi turned 27, a return to form for Argentina's other attackers would be the best present of all.