HAMPDEN will be a football-free zone for the best part of 2014.

Celtic will be glad to see the back of it. In recent times the national stadium has become a venue to be approached with some trepidation by Neil Lennon and his players. The Scottish Communities League Cup semi-final defeat to St Mirren on Sunday was the third time in succession that they had made the short trip to Mount Florida only to encounter failure once they got there.

The beauty of football is that any team on their day can beat anyone else. Upsets happen. When they start to happen as regularly as Celtic are finding, however, it is only natural to stop and question why. Have they become complacent because of their superiority? Are they not mentally tuned up? Are they uncomfortable playing at Hampden for whatever reason? Unsurprisingly these are all questions that fascinate Tom Lucas, a sports psychologist whose book Just Help Yourself, an alternative approach to dealing with life's stressful times, might just sell a few more copies around Parkhead this week.

Lucas has witnessed first hand Celtic's recent traumas and, in his expert view, the flat, lifeless performance in Sunday's capitulation to St Mirren, suggests a number of flaws in the players' mental make-up. "I've been at all of Celtic's recent games at Hampden and when I'm there I try to take a more pragmatic view so I can take in what's going on in front of me and not get caught up in the emotionality of the experience," he said.

"The thing that strikes me is that Neil Lennon needs to look at his preparation. What is he doing, or not doing, that makes these guys turn up and seem to forget that it's a semi-final or final? Are they treating these teams too lightly maybe because they've beaten them comfortably in the past?

"You have to reach a happy medium between overplaying the significance of a game and underplaying it. I think at the moment Celtic are underplaying it. They must have known St Mirren would have seen it as a one-off chance to reach a final and so would be willing to get in about them. But from the first whistle Celtic looked lethargic.

"That suggests that they were underprepared mentally for what they were about to experience. Complacency is a factor but there seems to be more to it than that. Maybe they need to change their build-up to these games, do something different to try to snap out of this cycle."

There is an irony that a club so accustomed to playing in the national stadium would appear to shrink in the big games while opponents who would have more of an excuse for a bout of stage fright have thrived. "If you look at their recent record, it seems there is something about playing at Hampden that doesn't agree with Celtic," Lucas added.

"They are continually struggling there, particularly in games where they have been strongly expected to win. There is quite clearly an issue with their preparation regarding the venue and a question mark over their mindset before they get to Hampden. They should approach these games bursting with confidence, with a positive approach, but that doesn't seem to be happening.

"Instead it is the other teams who appear to have greater desire and Celtic are struggling to match that intensity. Physical and mental energy is needed to win big games. On Sunday, St Mirren had both and Celtic had neither."

After a poor first half – made better only by Gary Hooper's late equalising goal – Celtic were expected to come out far stronger after the interval. Instead there was more of the same, much to Lucas's bemusement. "Questions have to be asked about just what was said at half-time in the Celtic dressing room," he said. "Gareth Southgate was once playing with England when Sven Goran Eriksson was the manager. Southgate said he was hoping for a Churchillian-type speech at half-time. Instead they got an Iain Duncan Smith. Maybe that happened again here."