CELTIC'S Europa League campaign gets off on Thursday night when Neil Lennon and his players travel to Brittany for their Group E opener.

Some Celtic fans are understandably concerned about their side's chances going into the fixture. After all, Rennes are currently sitting in second place in Ligue 1. They're the current holders of the French Cup. They've already beaten PSG this season. In Eduardo Camavinga, Rennes have one of the most exciting prospects in European football and at the end of August, the French club splashed out €20 million on Sporting Lisbon's Brazilian winger Raphinha.

All of this would suggest that Celtic are in for a tough night at Roazhon Park on Thursday, but there are a few signs to suggest that Rennes' impressive start to the season may well have a hint of good fortune about it.

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Five games into the new season, Rennes have three wins, one draw and a single defeat to their name. But the underlying stats from these fixtures suggest that their current league position is entirely unsustainable.

Expected goals (xG) measure how likely an individual effort is to result in a goal and then these chances are added up to give us a team's total xG from a fixture. Fundamentally, xG is used to determine whether or not a side are overachieving and measures the quality of goalscoring opportunities that a team creates.

Rennes have hit six goals in the French top flight this season but their cumulative xG from this period sits at 3.64 - nearly half of their total goals scored. This means one of two things: either Rennes' forwards are so good that they regularly score from low-probability shots (such as efforts from distance or a narrow angle), or they have been a little fortunate.

To put that figure into context, Rennes' xG is the lowest of any Ligue 1 side. Even bottom-of the-table Dijon, who have just one goal to their name, have an xG of 5.44. Celtic, for example, have an xG of 10.18 after six Premiership matches.

At the other end of the park, it is a similar story for Julien Stephane's team. After five league games Rennes have only conceded three goals, but have an xG against of 6.3. Again, this leaves us with two distinct possibilites: either Rennes' goalkeepers Edouard Mendy and Romain Salin (both have played a few games this season) are exceptional, or they have been lucky.

A look at last year's league table would suggest that Rennes have been overachieving so far this season. The Brittany club finished the season in 10th, 14 points off of a Europa Lague qualifying spot, just behind the likes of Nimes and Stade Reims.

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Rennes are certainly no pushovers but the underlying stats suggest that their current league position is not entirely representative. Over the course of a season, a team's xG and goals scored (and xG against and goals conceded) generally marries up. There might be a small swing either way, but this difference is rarely any more than three or four goals.

The fact that there is such a huge discrepancy between Rennes' goals and expected goals (both for and against) implies that the club's current success is inherently unsusutainable. Additionally, Stephane's side have the lowest tackling success rate in Ligue 1 and concede 13 shots on goal per game on average. There are areas where they look weak, and Celtic have the tools at their disposal to take full advantage.

It will not be plain sailing for Lennon's side, but the game is not as daunting as it may have initially appeared to Celtic fans.