Celtic look like they could be in for a difficult evening on Thursday night when they host Spanish giants Valencia in the knockout stages of the Europa League. Marcelino’s side have been somewhat stop-start this season but results have picked up in recent weeks and the Spaniards are being billed as favourites to win the match as a result.

Valencia have a number of high-profile players capable of producing match-winning moments in their ranks but their inconsistency this season has shown that they are far from invincible. The Spanish club are the bookies’ favourite for a reason, but there are still reasons for Celtic fans to feel optimistic about their side getting a positive result at Celtic Park.

Marcelino has plenty of expensive and high-profile attacking players at his disposal but Celtic fans will be encouraged to hear that despite the abundance of talent available at Valencia, they have failed to truly click this season, especially in attack. Players like Rodrigo, Kevin Gameiro and Goncalo Guedes are all dangerous players for the Spanish side, but all are guilty of being a little profligate in front of goal this season.

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Expected goals (xG) measure the quality and quantity of a team’s attempts on goal over the course of a match and, generally speaking, this figure will be around the same number as a side’s actual goals conceded. If a team is scoring more goals than their xG then it means they’re scoring goals that they reasonably shouldn’t be, and conversely if a club’s xG exceeds their goals scored, then they’re missing chances that they really ought to be putting away.

In La Liga, to say that Valencia have been wasteful in front of goal would be an understatement. Valencia’s xG is nearly 10 points higher than their actual goals scored, meaning they should really be 10 goals better off than they actually are at this stage of the season. No other side in Spain has as large a discrepancy between their goals scored and xG.

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Brendan Rodgers should feel cautiously optimistic about this. On one hand, Valencia are clearly adept at creating goalscoring opportunities, which is clearly problematic. On the other, they often struggle to put them away and with Scott Bain in fine form lately, the Celtic boss will surely fancy his chances against Valencia’s misfiring forwards.

Rodgers will no doubt be equally aware that Valencia have been guilty of being a little bit clumsy at the back on occasion this season. During their six Champions League group stage games this season, Marcelino’s defenders gave away three penalties, which accounts for half of their goals conceded in Europe’s premier club competition. Celtic’s forwards must focus on getting the ball into the box in the hope that they can perhaps tempt a defender into making a rash challenge.

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Relying on gaining a penalty is clearly a risky course of action, but Celtic should be able to cause the Valencia defence problems even without the referee's help. The Spanish club have one of the lowest success rate at winning the ball back in La Liga, winning only 20.5% of the defensive duels they attempt. This figure also drops to 19.2% when Marcelino’s side compete in European competition, so there is precedent that Celtic supporters can take heart from.

Valencia’s domestic statistics generally make for fairly impressive viewing, especially when the team’s inconsistency is taken into account, but Celtic fans will be encouraged by the fact that their numbers dip significantly when they play in Europe, particularly in attack.

The number of key passes - passes that lead to a shot - that Valencia average drops from 3.24 domestically to just 0.94 in Europe, one of the lowest averages recorded in this year’s Champions League so far. To be fair, four of Valencia’s six Champions League games this season were played against Juventus and Manchester United, but their key passes per 90 minutes only improved marginally against Switzerland’s Young Boys.

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All in all, then, it looks like Celtic will be up against it on Thursday night and while Valencia are certainly the favourites, there is still good reason to hope that Rodgers’ side will be capable of pulling off an upset. The Valencia attack isn’t quite firing on all cylinders as it should be and at the other end of the pitch, the defence have provided costly mistakes more than once this season. Celtic will need to be at their best - and hope for an off-night from the Spanish giants - but this isn’t unheard of this season and the stats suggest that there are weaknesses for Celtic to exploit. It is down to the players to do just that.