OLD habits die hard, but retain the potential to take your ambition to the grave with them.

Amid the inevitable introspection following the disappointing defeat in Amsterdam, the damning evidence of this will be unavoidable for Neil Lennon. The team that finally got the away-day monkey off their back with a first Champions League win outside Celtic Park in Moscow last year has since fallen back into the routine of returning home feeling unfilled and pointless.

Since that night against Spartak last season, when goals from Gary Hooper, James Forrest and Georgios Samaras secured victory, Celtic have lost to Barcelona at Camp Nou, been beaten by Benfica in Lisbon, were unable to recover a first-leg last 16 deficit against Juventus in Turin, and failed to take anything from the Group H opener against AC Milan at San Siro. Now they have come up short in the Netherlands on a night that held so much promise. Add the shock 2-0 defeat against Shakhter Karagandy in Kazakhstan in this term's play offs, and a goalless draw in Sweden against Elfsborg in the third qualifying round, and the harsh reality becomes clear.

The only win on the road since Moscow was July's 3-0 victory over Cliftonville in Belfast. So what is the root of the problem? It has been a mixed bag, from late despair in Barcelona to the flatness of Lisbon, being nullified in Turin and doing the same themselves in Elfsborg, the mistake-ridden night in Astana and unrewarded endeavour in Milan before the staleness of Amsterdam. However, there is a pattern. Celtic struggle to keep a clean sheet on their travels, despite the improvement in their defence and the consistent excellence of Fraser Forster. They shut out Cliftonville and Elfsborg, but have conceded in every other European away game in the last year.

At the same time, they have forgotten how to score on the road. Wednesday was another blank night to add to Milan, Astana and Elfsborg. Take away the goals in Belfast, and Celtic have not scored an away goal in continental competition since losing 2-1 in Lisbon last November. It is a fatal combination, guaranteed to dynamite any ambition to compete with the Champions League elite.

Fortunately, the must-win match against Milan in two weeks is at Celtic Park, by which time Lennon's players will likely have had their confidence restored. A victory in that game would mean Celtic overtake the Italians, who are also struggling to keep clean sheets or score goals. Then the stage would be set for a final day on which Celtic head to Camp Nou while Ajax face Milan at San Siro. If things have gone well against the Serie A side, the trip to Barcelona will be the ultimate test of nerve and courage for the Celtic players. It would also provide the perfect opportunity to prove they do indeed have it in their make up to truly punch above their weight as the section's fourth seeds.

Kris Commons' honesty in his appraisal of the performance in Amsterdam was laudable and the midfielder is every bit as forthright when challenged about the collective courage of the team away from Celtic Park. "I wouldn't say it's a bottle thing," he insisted. "Neither do I think there are any issues about playing away from home in Europe because, in the second half in Amsterdam, when it was 0-0, we were on top. If, just before their goal, Biram [Kayal] had taken his chance, it would have been a different game. But, that is the bit of luck you are looking for."

Lennon can only keep his fingers crossed that fortune smiles on his side again before the campaign is over, though the manager is the first to admit you have to make your own luck at this exalted level. Celtic have had large shares of it already, both good and bad, although nobody in the camp attempted to suggest Wednesday's result was anything other than a true reflection. Lennon is nothing if not a realist and, while he spoke expansively and confidently about taking a point from Amsterdam, he always knew this would be dependant on key players performing on the night.

Perhaps, too, it was a reminder this is still very much a Celtic team in transition. While the defence appears to have recovered from the loss of Kelvin Wilson, the midfield is still crying out for the physical presence of Victor Wanyama, and the goals-for column tells you how badly missed Gary Hooper is. Factor in the suspension of Scott Brown and gaping voids need to be filled.

Can Lennon do this in time for the visit of Milan? He has left his players with plenty to think about, not least regarding whether they will be given the chance to atone. "You can't be three or four players down at this level," he conceded. "I felt we didn't do ourselves justice. I'm angry, disappointed, frustrated. I don't want to be too harsh because there's still a lot to play for, but it's a good opportunity gone and we have to climb a bit of a mountain now."

Lennon is convinced the belief remains strong among the players, which makes what he described as shocking passing, flatness and a lack of aggression all the harder to explain or accept - "I'm not going to dig out individuals". But, while lessons must be learned, Lennon wants to move on and focus on Milan's visit. "I'm sure we'll play better and then things might look a bit more optimistic," he said. "But then we go to the Nou Camp and have to dig something out there."