There is no respite, but then it is the demands of Celtic, the competitiveness and the glory, that make the challenge so compelling for Neil Lennon.

The visit of Morton in the Scottish League Cup ought to be a secondary consideration when a tie with Barcelona is looming, but the expectation at Celtic Park is of triumph on every occasion.

Lennon can at least bring some variety to his starting XI. There are players on the periphery who want to prove their worth, among them Tom Rogic and the recent signings Teemu Pukki, Nir Biton and Derk Boerrigter will all feature tonight. "We'll have to, but it won't be drastic changes," said Lennon, who has invited Nicolas Mezquida, a 21-year-old Uruguayan striker, to the club for a trial. "Every tournament you are in you want to win it. I have to be careful, we want to keep the momentum going and Morton will come with nothing to lose. I know they're in a bit of a bad run at the moment, but the team has been pretty consistent in the past couple of seasons. I don't want this to be the game when they turn things around.

"It's not staking a claim, but saying 'I'm good enough, if you bring me in it will be a seamless transition'. That's what I'm looking for. They have the desire and have been patient. Their attitude is good and they know what is required."

Pukki has scored twice already since joining from Schalke last month, with both having been set up by Anthony Stokes. If that augers well for a potential partnership between the two, they are also rivals for the sole attacking role in the Champions League games.

Lennon believes that Pukki's form for HJK Helsinki and the Finnish national team suggests that he can be a prolific goalscorer for Celtic. He is also adamant the forward can play on his own up front, since he has the physical and technical ability, the pace and the movement, to trouble defenders. Has has also played the role for Finland, although the form of Stokes makes the Irishman the current first choice. "At my age it is important to play and develop," said the 23-year-old. "I really wanted to go somewhere I could be more part of the team and where the coach really trusts me. At Schalke, it wasn't really like that. I got the feeling the manager really wanted me here. After that, it was up to me. Of course, I still need to work hard to keep playing more and more."

Lennon has yet to win the League Cup as a manager and although he deflected any talk of aiming for the treble this season, the expectation is that Celtic ought to be too strong for any domestic opponent. There can always be setbacks, and players will naturally priorities the glamour ties of European competition, but the benchmark of success at Celtic is trophies lifted.

Lennon watched Ajax lose 4-0 to PSV Eindhoven at the weekend, and he has to be adept at sorting out his own priorities. He found time yesterday to say sorry to Tommy Wright, the St Johnstone manager, for discussing one of the Perth club's players, although he defended his view that Steven MacLean went down too easily in the area during Celtic's 2-1 victory last Saturday.

"If I have annoyed Tommy - and he's a very good friend - I apologise," Lennon said. "We were talking about a specific incident that may have changed the course of the game. I called it as I saw it. There was no offence meant. I don't remember calling Steven a diver. I never have called anyone a diver in the game."

Lennon was, though, irked by Stanley Menzo, the coach of Lierse SK, who questioned the fitness and conditioning of Tony Watt, who is at the Belgian club on loan from Celtic. Lennon shares the same concerns about the striker's approach to training, and has upbraided Watt himself about it, but was not so enamoured with Menzo. "I'm disappointed Stanley made it public, but he felt the need to do that," said Lennon. "Hopefully Tony will take that on board and progress the way we want. Physical conditioning is part of his game that he does need to work on. Put it this way, he prefers to play the football than do the physical side of things at times.

"But he's 19. He has to learn that to be a top player you need to put the work in as well as the talent. He will learn. You are hoping he will come back a better player. Tony has plenty of time in his career, enough people have told him now. He knows what is required of him and the ball is firmly in Tony's court. I will give him a call in the next couple of weeks and see how he has settled in."