NORWICH striker Teemu Pukki and Liverpool centre half Virgil van Dijk are rightly considered to be two of the best players in their respective positions in the Premier League, in world football in the case of the latter, at the moment. But early on in their Celtic careers neither man was particularly highly regarded by supporters. They both endured difficult starts to their time at Parkhead.

Neil Lennon referred to both Pukki, who failed to settle in Glasgow and moved on after little over a year, and Van Dijk, who quickly blossomed into exceptional defender, yesterday as he talked about the difficulties that both Boli Bolingoli and Christopher Jullien have experienced satisfying fans and justifying the substantial outlay on their services in recent weeks.

Critics may have been scathing about both Bolingoli and, to a lesser extent, Jullien since they arrived for transfer fees of £3 million and £7 million. But Lennon appreciates only too well from his first spell in charge that time and understanding is required with new acquisitions no matter how much they cost.

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He will certainly have no qualms about pitching both the left back and centre half into action against AIK Stockholm in the first leg of the Europa League play-off, a match which is of huge importance to him personally as well as his club, at Parkhead this evening.

“He [Van Dijk] played in Karagandy [in a Champions League qualifier in 2013] and then he didn’t play at home in the next one,” he said. “We lost 2-0 in Karagandy then won 3-0 at home. Virgil was on the bench for the second game.

“He [Pukki] did okay, but he was only a young lad then. He’s matured into a top striker now. He had a spell at Brondby. He’s become explosive since then and really kicked on in the last two seasons. He’s an exciting Premier League player now. I doubt very much that many people would have seen that coming. It’s a great story and great for him.

“I’m delighted it’s worked out for Teemu at Norwich, but it shows people often write players off here too quickly. That’s the environment we’re in. It’s almost ‘needs must, get him in and hit the ground running’. Or after three games it’s ‘he’s a dud, get rid of him’. We can’t take that approach, it’s impossible to take that approach.

“Maybe some will come good, maybe some others won’t. Chris is doing fine. Boli is lacking a bit of confidence, but he’s training well so I’m sure there’s more to come from him.”

Lennon continued: “Listen, Glasgow is a tough footballing environment. It takes a bit of character and the players are finding that as they go along. I’m certainly not writing them off. Other people can. But its way too early. We work with them, coach them and it’s out responsibility to get the best out of them as well.

“We’re determined to get the best out of the players here and let them enjoy their times here and enjoy their football. They haven’t hit the ground running yet, but we have hopes that they will and that they will come good.

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“We have to be patient. Other people aren’t patient and we understand that, we get that. We have to work with them. They are going to play tomorrow and hopefully that will be another step in the right direction for them to show everyone what they are really all about.”

Lennon recalled how he and his then assistant Johan Mjallby very nearly missed out on signing Pukki, who has scored four goals for Norwich in their opening two league games in England, after travelling to Finland to see him in action for his national team.

“Johan and I flew over to Helsinki,” he said. “We went to the Olympic Stadium and there was nobody there. It turned out we’d gone to the wrong city! We had to go back to the airport and hop on another flight to Turku. We ended up catching him for the last half hour of the game. He showed more than enough in that 30 minutes to convince us to take a punt on him.”

Lennon, too, has come under increased scrutiny since Celtic lost 4-3 to CFR Cluj of Romania at home last Tuesday evening to exit the Champions League before the play-off round for the second season running. However, he stressed he ignores the background noise and is focusing purely on an improved performance and positive result against AIK.

“The game and the team and the players and the manager get analysed to the nth degree these days,” he said. “You could be doing eight out 10 things right and they will focus on the two things that maybe aren’t right. That’s just the nature of where we are now, the game is analysed to death now by everybody.

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“I can’t read it or listen to it. I’d go mad. There are 50 different opinions. Just stick to what you believe in and stick to what you know. No-one knows the dressing room better than myself and my backroom team. No-one knows the players better than Browny and the others in there. You’ve got to trust them.”

Lennon has enjoyed success against Swedish teams with Celtic in the past; his side overcame both Helsingborgs and Elfsborg in Champions League qualifying during his first spell in charge at Parkhead. But he knows his charges must be at their very best to progress to the group stage.

“They are a strong team,” he said. “They play 3-5-2, have a good mentality and are rigid. They are good at set plays and have [Sebastian] Larsson. It isn’t going to be a walk in the park. I want us to be purposeful and set a good tempo. When we do that we are quite good, very good actually.”