Lionel Messi
Lionel Messi has trained ahead of Barcelona's second leg with Paris Saint-Germain. Reuters

Barcelona looked in a commanding position to make the Champions League semifinals when they led entering the final stages in the Parc des Princes last week.

But, having twice relinquished advantages in the final 11 minutes to Paris Saint-Germain, the quarterfinal tie remains in the balance at 2-2 heading back to Camp Nou for the second leg.

To add further doubt, Lionel Messi and Javier Mascherano suffered injuries in that contest and face a race against time to be fit for the return. It is the health of Messi, understandably, that has caused most conjecture. The majestic forward trained on Monday and Tuesday ahead of the game, although there remains significant doubt that his hamstring strain will be risked, at least from the start.

Certain cynics have long attempted to label Barcelona as a “one man team,” and the Blaugrana may well get a chance to disprove that theory on Wednesday. It is, though, a laughable notion to begin with.

Messi ranks as, at the very least, one of the best players to ever play the game and he would stand out as a star in any side. Any coach worth their salt would set-up their team to get the best out of a player of his incredible ability.

But the rest of the squad is hardly devoid of quality. There are likely to be eight World Cup winners in Barcelona’s team against PSG, while the duo of Xavi and Andres Iniesta are two of the finest midfielders in history and have both recently been voted among the best three players in the world. Not a bad collection of stiffs.

Barcelona’s confidence, in the event that Messi fails to make the starting lineup, should also be boosted by the performance of his stand in at the weekend.

Cesc Fabregas has struggled to adapt as he would have liked since his return from Arsenal almost two years ago and often there has been a sense that he has gotten in the way of rather than complimented Barcelona’s incisive attacking play. But in Messi’s place as a false nine against Mallorca on Saturday he flourished and scored a hat-trick. It was also a position he excelled in for Spain at last summer’s European Championship.

With Alexis Sanchez also discovering some form -- scoring twice and providing two assists -- PSG’s defense would be misguided to have any complacency in Messi’s absence.

It was a backline that was for the most part extremely impressive in the first leg. Thiago Silva showed why Barcelona were so keen to sign him last summer and why he is rated by many as the best center-back in the world with his terrific organizing, positioning and tackling.

Until Barcelona scored late in the first half, it had been the ideal performance by the home side. What on the face of it was an attacking lineup -- featuring Lucas Moura, Javier Pastore, Ezequiel Lavezzi and Zlatan Ibrahimovic -- helped Carlo Ancelotti’s side to be threatening on the break while also compact without the ball as the nominal wide midfielders became extremely narrow.

A similar lineup is likely to be fielded at Camp Nou when PSG will need to score in order to have a chance of progressing. With Barcelona set to be without Mascherano and Carles Puyol in the heart of their defense, the Ligue 1 leaders will certainly have hope that their quality attacking quartet can cause real problems.

But as Barcelona illustrated in the last round when they overcame a 2-0 first-leg deficit against Milan by winning the return match 4-0, they are a different side at home in Europe.

Since Barcelona began their incredible spell of success under Pep Guardiola in the 2008-09 season, in six knockout ties they have either drawn or lost the opening leg away from home before progressing back in Catalonia.

Like so many sides before them, PSG’s ability to try and restrict space will be undermined by the large surface at the iconic Camp Nou. And with Jordi Alba fit, having missed the first leg, to join Dani Alves marauding forward from full-back, Barcelona should overwhelm PSG, with or without Messi.

Prediction: Barcelona 3-1 Paris Saint-Germain