They sit either side of the head coach in the squad photo. Both enjoyed stunning form for their respective clubs last season. One is quiet and shy, the other charismatic and controversial. One still has yet to fully win over the more militant sectors of the Argentine public, who still question his commitment to the shirt. The other is often labelled 'the people's player'. But while the coach vows to centre the team around one of them for the next 10 years, until just weeks ago the other was not even going to make the squad.

To Sergio Batista's left sits Leo Messi. To his right Carlos Tevez.

While Messi is the undisputed reference point in the Argentina national team, the fact that Tevez nearly missed out on the Copa America squad initially points to the formidable attacking talent that Argentina has at its disposal.

Headed by Messi and joined by Sergio Aguero, Gonzalo Higuain, Ezequiel Lavezzi and Diego Milito, not to mention Angel Di Maria and Javier Pastore, the attacking options open to Argentina are vast.

But the controversy over Tevez not being called up for a number of Argentina's friendly matches also points to problems - and the pressures - surrounding the Argentina national team, and specifically for the coach who replaced the irrepressible Diego Maradona, Sergio Bastista.

As far as the local media were concerned, the issue with Tevez wasn't to do with competition, ability, form or style. It was political. Of all the players in the squad, the Manchester City striker was the only one to publicly defend Maradona after the World Cup. That was both a snub for Batista, but also an indirect criticism of the AFA president Julio Grondona, who chose not to renew Maradona's contract.

When Argentina played Brazil in Dubai last November, Tevez and his club reported in as injured, only to then play days later for his Manchester City and score twice against Fulham. It is anecdotal that Maradona in the stands at Craven Cottage that day.

Whether this situation was blown out of all proportion or whether there was real substance to it, in not calling up Tevez - for purely sporting reasons according to the coach - Batista was denying himself a player who was in dazzling form for his club.

Yet there have been question marks over Tevez and his performances with the Argentina side. He doesn't score as many goals as he does at club level and at times his willingness to track back and work for the team has hampered his own chances of being selected to play a more out-and-out striker's role.

Now that the squad has been finalised, and Tevez is in that squad, Batista admitted (via twitter, he named his preliminary squad on his facebook page) that he is still undecided over his front three. "The competition [for places] up front is enormous; it's a big dilemma for me for our debut," he wrote on Tuesday.

In the meantime, while Tevez battles it out with Lavezzi and Di Maria for a spot in Batista's preferred starting eleven, the project centres around Leo Messi. The Barcelona forward is essentially given a free role with the national team, nominally starting out as the central striker, he is allowed to drop deep to collect the ball or drift out wide.

But it is precisely that mobility, and the system at Barcelona in which Messi shines, which Argentina has yet to polish. From day one Batista has stated his admiration for the way the Catalan club play, and has said he hopes to replicate that as far as possible.

The Copa America represents the test of how far Batista has taken Argentina forward since the resounding 4-0 defeat to Germany in the World Cup quarter finals.

Batista has looked to develop a 4-3-3 system, with his preferred midfield of Cambiasso-Mascherano-Banega. At the back, 37 year old Javier Zanetti remains the first choice on the right hand side of defence, with Marcos Rojo of Spartak Moscow on the left. The central partnership is expected to be Gabriel Milito and Nicolas Burdisso, with Sergio Romero in goal.

While the focus is inevitably on the attacking flair the side has the potential to deliver, improving the defensive unit is as important for Argentina in this tournament.

As two-time World Cup winners, as hosts, and having lost the 2007 final 3-0 to Brazil, the pressure on Argentina is extremely high. But with the added rhetoric of aiming to play like Barcelona, there is the added demand from the supporters to see great football.

Batista has repeatedly said the 2014 World Cup is what Argentina are preparing for, but realistically anything other than winning the competition will be viewed as a failure.

Joel Richards regularly writes about Argentine and South American soccer for various outlets, including The Guardian, The Football Ramble, and FOX Soccer. You can follow him on Twitter at @joel_richards .