It is a little bit early for Halloween but Celtic regurgitated a familiar horror showing in Austria as their defensive ghouls came to the fore against Salzburg.

Having started well and nicked the early goal, Brendan Rodgers’ side then collapsed in a second-half onslaught as the hosts ran out comfortable winners. Indeed, if there is a silver lining to draw from the encounter it would be that without a couple of decent second-half stops from Craig Gordon the scoreline might have looked a whole lot worse.

Defensive frailties and a cheapness with which goals are handed out has become a frustratingly common occurrence for Celtic, with the European stage in particular offering a painful sense of deja-vu.

If the Europa League was supposed to provide some calm in the face of previous Champions league storms against the likes of PSG and Barcelona then last night’s outing offered some food for thought.

Five things we learned:

1) That Celtic look tired

It is hardly a revelation but there is a lethargy and a lack of fire to Celtic’s play. There has been a sense of apathy around the team for much of this season, matched by the style of football on offer.

There were brief glimpses in the early stages that the Parkhead side were capable of finding some of their fluency but all resolve was lost as soon as Salzburg started to ask some serious questions of their own.

There has been a hangover weighing heavily around the team ever since the fall-outs of the summer and the exit from the Champions League.

his was a sluggish performance and most galling of all for Rodgers was the ease with which Celtic continually conceded possession, even when under little pressure. It meant they spent much of the game camped inside their own half, inviting danger onto them.

2) That Celtic are a better team with Scott Brown in it

The Parkhead captain has been a mainstay of the midfield and his influence has been difficult to underestimate under Rodgers’ watch.

In fairness, his presence did little when Celtic came up against the heavyweights in the Champions League last season as some sobering scorelines were handed out but there was a point last night when he might have been able to bring the midfielder into play.

One of the positives, though, was the first-half performance of Youssouff Mulumbu with the former Kilmarnock midfielder particularly impressive in the opening stages.

It raises the possibility of the player getting some game time in beside Brown at some stage this season, particularly since Olivier Ntcham has blown hot and cold in these early weeks of the campaign.

Ntcham was the subject of serious interest from Porto this summer with his representatives keen to engage in talks while Celtic were adamant that he would not be sold.

Since then the player hasn’t ever quite managed to find the momentum of the latter part of the previous campaign when he was one of the standouts for the Parkhead side.

3) The jury remains out on the Leigh Griffiths and Odsonne Edouard partnership

The early signs against Salzburg looked promising, particularly with the manner in which Edouard, the club’s record signing this summer, rolled his way past Andre Ramalho to give Celtic the lead.

However, the two players didn’t link particularly well and as Salzburg set up taking the game to Rodgers’ side there was a feeling that neither Edouard nor Griffiths could get a hold off the ball to take some of the pressure off the middle and defensive men.

In the same way Edouard still looks raw – inevitable for a 20-year-old – and could use his physicality a bit more.

The duo looked out of kilter together, however, and there was little understanding between them. Griffiths, too, looks as though he is short of match fitness and seemed to struggle to get about the pitch against Salzburg.

4) Brendan Rodgers was keen in bringing in another right-back to the club this summer and you can see why

Mikael Lustig looks like a player short on confidence and form and his display against the Austrians will have done nothing to alleviate that.

The Swede had a decent World Cup in Russia this summer but he seems leggy and slow, as if he has never quite got into the groove of the season.

The full-back was caught off guard when Dabbur netted the equaliser and from there the roof fell in on Celtic as the hosts scented blood. The cross for the Austrian’s second goal came from his side of the pitch and there is a growing sense that he needs a breather from continued exposure to the first-team.

5) Celtic’s games against Leipzig will determine their fate in Group B

There was always a feeling that it would be Salzburg who would top the group and that is exactly how it appears to be playing out.

Celtic are next on the road following the international break to go and play the German side in a game in which they really need to take something.

With Rosenborg sitting at the bottom of the table it looks like being a fight between Celtic and Leipzig as to who claims the second spot to progress to the knockout stages after Christmas.