Two mammoth games that could define Barca\'s season lie ahead on the horizon, but first they must face a potential banana skin at the Ciutat de Valencia.So, Real Madrid have negotiated their toughest title run-in pre Clasico, winning two out of three as they thumped Osasuna at the Reyno de Navarra 5-1 and Atletico Madrid 4-1 at the Vicente Calderon. Curiously, they dropped two points against Valencia at the Santiago Bernabeu, a ground that up to a few weeks ago had been their fortress.Now, for Barcelona to keep the Liga race a nail-biting affair until the end of the season, they must do their part in overcoming one of their tougher tests: a trip to Levante.Not many would have expected the Valencian outfit, relegated in 2008, whose entire transfer budget is not enough to rent Lionel Messi for a week, to be one of Barca’s main hurdles in the title hunt. But they have enjoyed a remarkable, even miraculous resurgence. Winning promotion just two seasons after their drop, they are now challenging for a place in next season’s Champions League.Like Real Betis, Levante made a blistering start to La Liga this term, but unlike the Andalusians, who have since faded to mid-table mediocrity, Juan Igancio Martinez’s side have kept battling throughout the campaign and apart from the opening three matchdays, they have not dropped any lower than seventh in the table.Levante are the classic grafters, a team of hard workers who bind together to suffocate their more illustrious opponents. Real Madrid know all about their defensive resilience and counterattacking threat when they lost 1-0 at the Ciutat de Valencia earlier in the season. It’s the same trap waiting to be sprung against the Catalans.With a date against Chelsea in the Champions League looming and suspension worries ahead of the Clasico, Pep Guardiola could decide to rest several key players again, much like he did last week at Zaragoza. The Catalans were lucky to grind out what ended in a comfortable-looking 4-1 win against their 10-man opponents, but they were outplayed for much of the opening period, and could have gone 2-0 down before fighting back to equalise and subsequently storm away.Another squad-rotation approach might not work for Guardiola at the Ciutat de Valencia. Levante will not shy away from putting every man behind the ball and should Pep start without the likes of Xavi, Andres Iniesta, Alexis Sanchez or even – albeit unlikely – Lionel Messi, they could find themselves just running into a brick wall.Even more precarious for Barca is their need to constantly shuffle their back line. Levante will hit the Catalans on the break and they will relish taking advantage of a defence that is not completely in sync. Juan Ignacio’s men are extremely effective in front of goal. Despite averaging only 41.5 per cent of ball possession, the second lowest in the league ahead of just Racing Santander, and 4.03 shots on target per game – also one of the poorest – they have scored 46 times so far, the seventh-best attack in the league.