Lennon aware there is work to be done ahead of crucial tie with Helsinki

The 4-0 defeat by Ajax in Amsterdam on Saturday was not the conclusion anyone in the travelling party wanted, yet it could be the most significant result of a two-week warm-up schedule designed to get the Clydesdale Bank Premier League champions ready to face Hjk Helsinki in their Champions League third-round qualifying tie next midweek.

The heavy defeat confirmed there is still much work to be done in terms of fitness, gaining match sharpness and organisation. With a number of players having left this summer, Lennon is seeking to establish new partnerships in defence, and the disjointed displays not only in Amsterdam, but also against German sides Augsbrug, Stuttgart Kickers and Vfr Aalen, underlined this is some way from a happy conclusion.

Lennon has reiterated he wants to sign an experienced central defender. On pre-season showings, there is doubt this is not just a wish but a necessity.

The lack of goals during the tour – a 2-1 victory over Vfr Aalen the only match in which the Parkhead side found the net – will be another concern for Lennon. He will take some solace in the fact Georgios Samaras has yet to make his return, the Greek having been afforded time off following his participation in the European Championships. But, to pin your hopes on an enigma like Samaras is not a safe insurance scheme.

Others, including Adam Matthews and Emilio Izaguirre, did not see their first action until the Ajax defeat. They will benefit from the hour they got chasing shadows and the ball, though it is questionable if Lennon will again deploy them in the same wing-back roles as the 3-5-2 system he elected to use against the Eredivisie champions was undone by the swift and incisive Dutch.

Lennon held his hands up and admitted he got his formation wrong, and he quickly reverted to a flat back four after goals from Siem de Jong, Kolbeinn Sigthorsson and Thulani Serero left Celtic in complete disarray. For a back three to work, the defensive midfielders must offer solid protection and prevent opponents having the time and space to thread balls down the channels of the centre-backs.

That did not happen in Amsterdam, where, individually and collectively, the players came up short. The absence of Biram Kayal – the protective boot on his left ankle is due to come off today – was sorely felt, though the change in tactics worked until Charlie Mulgrew was sent off and Daley Blind scored the resultant penalty.

Any defeat, even in pre-season, is tough to take, but it was the gulf between the teams which is most disconcerting, given that Celtic are striving to reach the Champions League group stage, where teams of the ilk of Ajax await. "We would definitely rather make the mistakes in these friendlies than in the game against Helsinki," said Matthews, trying manfully to garner a positive from the match.

"We tried a few formations against Ajax and, obviously, we would rather see they don't work now than go into the game against Helsinki and see it there. As players, we know we didn't do enough, and we've got to do better.

"I don't think we started that well and, once they scored the first goal, we gave them two really sloppy goals. After that, we did all right, but they were the much better team. That's the level we need to get to. They are a great team in Europe, and that's where we want to be."

Matthews will be relied upon heavily this season and his manager will be reassured by the fact the Welshman is not prepared to simply dismiss this defeat as the kind of blip which can happen in pre-season. "We didn't do ourselves justice," said Matthews. "We were not competitive enough. We know we've got to do better and, hopefully, against Helsinki we can."

Celtic will have the chance to recover their confidence against Norwich and Inter Milan, although Lennon might be content just to see his defenders perform efficiently and his forwards offer greater menace.

The thought of facing Helsinki – who Lennon hopes to watch in the second leg of their second qualifying round tie against KR Reyjavik in Iceland on Wednesday, with the Finnish side leading 7-0 – without significant improvement in both departments would add unwanted anxiety to a fixture on which so much rests for Celtic's season.

"We're still in pre-season mode, but now we really need to knuckle down ahead of the Norwich and Inter Milan games," said Lennon. "You learn a lot about a team in defeat. We're not demoralised by any means. We do know there's a lot of improvements to make.

"We've already learned a lot from Ajax. It's a marker for where we are and where we need to be to challenge for the Champions League. We take a lot of positives from it despite the manner and how heavy the defeat was."