Barcelona and Paris Saint-Germain will renew their rivalry in the quarterfinals of the Champions League.

This is the second time in three years that the sides face off at this stage in the tournament. In 2012-13, the two sides battled to a 3-3 aggregate over two legs. However Barcelona had managed a 2-2 draw in Paris and was thus able to advance.

But even that tilt was not that simple. Barcelona held one-goal leads throughout the opening contest and even scored a seeming game winner in the 89th minute. But PSG kept coming back and scored in the third minute of stoppage time to secure a draw at home.

In the second leg of that tie, the Parisian side held a 1-0 lead after 50 minutes and looked the favored side to move on to the semifinals. But Lionel Messi came on the pitch and tilted the balance in his team's favor, helping create the tying and deciding goal in the tie.

This season the two sides faced off in the group stage with Paris securing a 3-2 win in the first meeting before falling 3-1 in the group deciding match.

This suggests a tilt that could come down to the wire but there are a few major points to be noted. Here they are.

Lionel Messi is the man to watch

During the first leg of the 2013 quarterfinal, Messi picked up a fateful knock that would not allow him to start the ensuing leg. Without him, the team floundered and looked as susceptible as they come. He arrived on the pitch and despite not being at his best was able to turn the tide. But that would provide prophetic as Barcelona imploded in the ensuing round against eventual champion Bayern Munich. Everyone remembers that score - 7-0.

Messi is not hobbled over any longer. And he is in far better form that he has been in since 2012. PSG has yet to see him at this peak, save for the second match of this season's group stage. And we all know how that turned out.

In essence, a strong Messi is a dangerous one and could ultimately decide the tie.

No Zlatan Ibrahimovic

For PSG it might look dreadful to not have Ibrahimovic in the first leg (he received a red card against Chelsea), but the team actually played better without him. Interestingly, the team actually won against Barcelona without the Ibrahimovic on the pitch.

And that is actually not that surprising.

With the Swedish giant, the team is almost forced to play to him as the top offensive weapon. The problem is that Ibrahimovic is not the most mobile of players and this makes him slightly easier to defend.

Without him, the attack becomes less predictable with Javier Pastore, Ezequiel Lavezzi and Edinson Cavani providing speedier options in attack.

Formation?

One of the most interesting features of this match should be the formation Barcelona chooses to play.

In the 3-2 loss, Luis Enrique opted for a 4-3-3, which was easily countered by PSG's own 4-3-3. Barcelona simply could not recover from the vicious counterattacking of the French side and was constantly decimated on this front. The numerical advantage in the midfield was neutralized and speed outdid anything Barcelona had up its sleeves.

Enter the 3-5-1-1. This is a formation rarely ever employed by the Catalan side but it helped Enrique's club ensure possession in the middle of the pitch. With PSG playing a 4-4-2, the Barcelona formation protected the side from speedy counters as it retained three options at the back instead of the usual two.

Instead of employing wingbacks, the team instead opted for a three man midfield and two wingers behind Messi and Luis Suarez as a "10" and striker respectively. It certainly gave Barcelona a lot more attacking options and overwhelmed PSG in the 3-1 win. What helped the formation was that Enrique put both Javier Mascherano and Sergio Busquets in the middle of the park, allowing the team two holding midfielders that could easily help retain the ball. It ultimately turned into a 3-2-3-1-1 in defense, frustrating PSG in the middle of the park.

That said, it wasn't a perfect strategy. With Pedro and Neymar on the flanks and neither competent defensively, Barcelona was susceptible to counters down the wings. That PSG could not take advantage in that match is one thing. But having experience that formation, coach Laurent Blanc will surely be ready for it if it reappears. And then Barcelona might regret that decision. 

Prediction: Barcelona is the team of the moment and should hold the edge heading into the quarterfinals. But PSG is no pushover and has sufficient power, particularly in the air to outdo Barcelona.