THE time for reflection is limited.

Neil Lennon had barely 30 minutes after his team had won the double to celebrate with his staff before the questions came. The matches will follow in quick order.

The Celtic manager has to sort out his contract, tell the unwanted players that they can leave, persuade the wanted to stay, sign new ones and fit in a holiday before another season starts with training on June 20. That is, in under four weeks from now. Then on July 16 or 17 Celtic will embark on what they hope are three successful rounds of qualifying for the Champions League group stages.

It is a schedule so tight it almost squeaks. But while the future is compelling, it is right to look back briefly on the past.

The achievements of Celtic and their manager have been wilfully underrated this season. Lennon and his team have been criticised for what they did not do, namely win the league by November and fail to gather a domestic treble. Yet a double was achieved and the club reached the last 16 of the Champions League. The victory over Barcelona was given justifiable prominence but to beat Spartak Moscow twice and to qualify from a group containing subsequent Europa League finalists Benfica was astonishing.

Lennon remains irked at the lack of credit offered to his side. "It was important to win another trophy because, if we hadn't, then it's a single-trophy year," he said after the 3-0 dismissal of Hibernian in the William Hill Scottish Cup final. "And the Champions League seems so far away in some people's eyes. 'It was lucky'. You get that thrown at you. I'm fed up of people nipping at the team. They might nip at the team because of me, because they don't like me. It doesn't matter. This team deserves a bit of respect."

He is aware, though, that the challenge has been set by the success he has already achieved. "It's going to be difficult to improve that," he said of season 2012/13. "Are we going to get another run in Europe like that? It's going to be very difficult. And that's the reality of it."

The matters of agreeing to a revised contract and assembling a squad are dwarfed by the difficulties presented by the Champions League. "I don't like the qualifiers; they're the nervy games," he said. "We've got three to negotiate. That means you've got to get your pre-season spot on, you've got to get the players in the right frame of mind, but I think what they tasted this year might motivate them for a little bit more. I would cut your hand off right now to be in the group stages.

"Beating Moscow twice was the real highlight [this season]. Certainly, beating them to qualify. There was so much riding on the game. The way we played second half, particularly the last half hour, with great maturity . . . I mean, let's get it right, Spartak Moscow were a pretty good side."

The final against Hibs brought its own fears and Lennon admitted to being extraordinarily nervous. "There was so much riding on it in terms of 'can we do the double?', the Hampden thing, the Hibs thing and finishing the season with another trophy. It might seem a bit unfair, but that's the reality of being the Celtic manager."

The reality of being the Celtic manager is that Lennon is now charged with winning a treble next season and also achieving success in Europe.

Surely his stock as a manager is in danger of going down? "What else can I do? I just have to keep motoring on and try to improve and progress the club as best we can. I know what a lot of people think of me in Scotland, but there you go. I'm really proud of what I've achieved, what the backroom staff have achieved and what the players have achieved this year," he said.

The year has offered lessons, though. "You gain more experience, more knowledge of the game, formations, that type of thing. What we have done this year is show we know how to win. I know people say there's a lack of competition, but everyone competed in this [the Scottish Cup] and we won that. Everyone competed in the Champions League, all the top teams, and we did pretty well in that as well. So I want this team to get the credit it deserves," he said.

"I've got a couple of weeks away in June so I'm looking forward to that," he added. It then starts all over again.