Inside look how Barcelona could line up against Real Madrid with or without Lionel Messi on Saturday night.

VI-Images Getty Images Europe

Lionel Messi is back in full training ahead of El Clasico clash as Barcelona takes on Real Madrid at the weekend, but whether the 28-year-old will start after two months on the sidelines is still unknown.

Barca boss Luis Enrique handed Luis Suarez his debut in the corresponding fixture last season. The Uruguayan striker was available again after a four-month ban and was given a surprise start as the Catalans lost 3-1 at the Santiago Bernabeu.

More from FoxSports

Messi's situation is different, however. The Argentine attacker has been sidelined since Sept. 26, when he damaged knee ligaments in a La Liga match at home to Las Palmas. So even though he is back training with his teammates ahead of the trip to the capital, playing him from the start could constitute a risk as he is still short of full fitness.

"We are happy with the job we have done so far despite being without the best player in the world," Suarez told reporters on Wednesday. "We have done a good job without Messi on the pitch. We know that Messi can change a game at any time and he is above the rest."

It's a dilemma. Barca fans will want their star man managed correctly in order to avoid further time on the treatment table. But they will also hope to see him out on the pitch in one of the biggest games of the season: El Clasico.

The most likely scenario at this stage would be for Messi to start on the bench at the Bernabeu and if he does so, Luis Enrique has a number of options available. The Barca boss could stick to a 4-3-3 formation with Andres Iniesta moving into an advanced role as he did so often in the Josep Guardiola era. Iniesta has regularly played as part of a front three for the Blaugrana and in this case the midfielder would slot in on the right, with Neymar on the left and Suarez starting centrally.

Another alternative, and one tried out briefly by Luis Enrique against Getafe and BATE Borisov, is to play Sergi Roberto as a winger in a formation that could be a 4-3-3 but would more likely resemble a 4-4-2. That will depend on Messi but also on whether midfielder Ivan Rakitic is ready to return from injury on Saturday.

It looks likely the Croatian will feature at the Bernabeu, but if he and Messi are both deemed unfit to start, Luis Enrique will be forced to pick either Munir El Haddadi or Sandro in attack alongside Neymar and Suarez, with Sergi Roberto in midfield. If both Messi and Rakitic are passed fit to start on Saturday, Luis Enrique will have to decide between the Croatian's big-match experience and the fine form of Sergi Roberto.

The Catalan midfielder would be extremely unfortunate to drop out of the starting XI following his impressive performances of late, yet Rakitic alongside Sergio Busquets and Iniesta is Barca's first-choice midfield in theory.

In defense, meanwhile, the Barca boss could decide to call upon the extra height and pace of Jeremy Mathieu at centerback. The French defender started both El Clasico clashes in La Liga last season and scored in the 2-1 win at Camp Nou. Thomas Vermaelen is another alternative alongside Gerard Pique, although Javier Mascherano remains the most likely partner for the Catalan. Claudio Bravo will start as he has habitually in La Liga this season in goal.

Barca head into the first El Clasico of the season riding a four-match winning streak in La Liga. They are three points clear of Real at the top of the standings.

"To arrive at the Bernabeu Stadium with a three-point advantage over Real is great," Suarez added. "I don't know if we are favorites but Real is always Real and we know what they can do so must be very focused. It's always special to play in Madrid and I have fond memories having made my Barca debut there last year even though the result was not what we expected."

FOXSoccer.com's newswire services contributed to Ben Hayward's piece from Goal.com