IT HAS been the most challenging season of Neil Lennon's short managerial career.

And it will start all over again in 24 days.

By the time the Hoops, who have just secured the club's first double since 2007, return to pre-season training on June 20, Lennon fervently hopes the green light will have been given to continue building on what has already been achieved.

The meeting he will hold this week in London with major shareholder Dermot Desmond and chief executive Peter Lawwell is expected to provide most, if not all, of the answers to the questions the manager wants to ask.

Lennon knows the club's business plan requires, at some stage, the sale of the rough diamonds he has helped turn into hot property, with Victor Wanyama, Gary Hooper and Fraser Forster on the shopping list of rich buyers in England.

What he wants to hear is that, having pulled this young group together to become a side good enough, not only to win four domestic trophies in the last three seasons, but also to earn the club £25million through their exploits on the European stage, the money generated from sales will be recycled to allow him to try and build an even better team.

Lennon also wants to find himself in a position to offer new contracts to key personnel he believes must be retained if his plans are to be put in place.

Which is why, while last week was a crucial one in terms of signing off the season on a high, the coming few days could be considered even more important.

He believes the ambition of the men who run the club matches his own. But it is how all parties see realising this ambition which will be at the heart of their discussions.

The manager said: "I know one or two players will go, and I'm prepared to accept that for the health of the club, so long as, if one of these players do go, we can re-invest the money and improve the squad.

"That's the way we have worked for the last three years."

And worked successfully, given the return in terms of increased value of the squad and the trophy haul.

The average age of this group remains relatively low, with the vast majority entitled to believe their best years are still ahead of them.

Lennon certainly subscribes to this theory, and recognises the necessity of retaining the core of what he has built if they are to achieve even higher goals.

"That will be important, and I need to improve the squad in some areas, too," he said.

"I need to hold on to some players, but that might prove to be very, very difficult."

Ironically, that's because they have done so well while at Parkhead, particularly in Europe, where most managers looking for potential signings prefer to make judgments on players operating in what is perceived to be an inferior league.

Lennon would himself hope to be able to shop around, albeit occasionally, in the market where players carry price tags in the £5m-6m bracket.

But aided by chief talent scout John Park, he has proved very adept at finding bargains, including £900,000-purchase Wanyama and Hooper, who was a tad more expensive but no less incredible value at £2.4m.

The striker's 81 goals in three years at the club has led the manager to describe him as "an absolute master and priceless" though the validity of the latter part of that tribute is likely to be put to the test.

It could reasonably be argued Lennon has shopped even more successfully in the Bosman basement, with Joe Ledley the pick of the bunch who have arrived with no purchase price attached.

The Welshman again proved his worth with the final goal in Sunday's rout of Hibs, his 10th of another highly-impressive season.

Lennon was on his feet applauding his finish and energy, and said: "Joe is good at that. He ghosts in there.

"He's got a great goal scoring record for a midfield player, and popped up again with yet another great finish on Sunday.

"Joe is one of my best signings. I would not describe him as an unsung hero because the fans love him, as do his team-mates.

"He is just one of those consistent players, and a machine in terms of athleticism.

"Joe's only getting better and better. He's still only 26, so he has so much in front of him."

Which Lennon wants to see him produce in a Celtic shirt.

Like Anthony Stokes, Hooper and Wanyama, Ledley has been engaged in negotiations over a new contract to reward him for the job he has done.

"It's important to keep people like Joe here, if they want to stay," said Lennon. "They have been at Celtic for three years now and have won things, played in Europe and they love the club.

"So, I think it is important to have people like Joe around the place for a little bit longer."

Of course, not everyone can be retained if the squad turn-over required to keep things fresh and to allow room for younger players to develop is to be maintained.

With the 59-game season finally over, Lennon will take the chance to sit down with those who are either coming to the end of their contract, or simply coming to the end of their time at Parkhead.

Cards will be on the table, and honesty the currency of choice.

Paddy McCourt is expected to be on his way, while question marks remain over the on-loan Rami Gershon.

Thomas Rogne is another who Celtic have tried to re-sign on a new contract, but who may now find the exit door.

Chances are the Norwegian defender will not be alone as time runs out for those who have not quite made the grade.

The players who do go will leave with Lennon's thanks as the 41-year-old respects the efforts made by each and every one of the players operating under his charge.

However, the man who has joined Jock Stein and Billy McNeill as the only people to be able to claim they have won a double as a player and boss of Celtic, understands that, at this level, to stand still is to go backwards.

With the 125th anniversary season celebrations over, it is next year and beyond that matters.