AS Celtic are discovering, rare is the opportunity in sport to simply enjoy the moment.

Any offers of congratulations tend to be followed up with the demand for an encore. How do Neil Lennon and his squad improve on that next year? Can they complete a domestic treble? Can they reach the quarter-finals of the Champions League?

These are matters that will no doubt shape the conversation when Lennon sits down with chief executive Peter Lawwell and Dermot Desmond, the Celtic majority shareholder, in the next week or so.

Individual players will have their own sources of motivation as well. The prospect of Champions League football remains a draw, although Celtic will need to safely navigate a path through three qualifying rounds just to dine at the top table. Making it through to the knockout phase from the position of fourth seeds – as they did in the season just finished – will take another supreme effort. Without European football, another fairly humdrum domestic season without Rangers might not hold the same appeal.

The lure of the Barclays Premier League may prove irresistible to some. For Fraser Forster, it may be the difference between spending next summer at the World Cup finals and spending it in his back garden. Forster is not one for sweeping, brash statements but it was not difficult to detect a note of concern as he spoke about his chances of being included in Roy Hodgson's squad for the finals – assuming England qualify, of course.

After being named in three of Hodgson's previous squads, the Celtic goalkeeper's omission from the group that will face the Republic of Ireland in a friendly at Wembley tomorrow was a surprise.

It may have got Forster thinking, too. Hodgson will make all the right noises about keeping tabs on his progress next year, especially if Celtic again make the Champions League, but it stands to reason that Forster's prospects of making the plane to Rio will be greatly enhanced should he be playing under the manager's nose and appearing on Match of the Day every weekend.

Forster didn't declare as much but his assertion that he would "do whatever is necessary" to force his back into international contention suggested he was at least keeping his options open. "It's a tough one," admitted the 25-year-old. "Celtic has been fantastic for me. This season couldn't have gone much better

"It's disappointing not to be in this England squad, but I've got to be looking towards the World Cup and trying to be on that plane. So I'll just have to do whatever is necessary to make that squad. It's a World Cup year and World Cups in Brazil don't come around very often. That would be something special to be involved in. That will be one of my main aims next season. I'll do whatever I can to force my way on to that plane.

"Was it a body blow not to be in this squad? Well, yes. That's where you want to be. Having had a taste of being in an England squad before and after Christmas, that's what you're aiming for. Once you've been in you want to be in every time. I didn't get an explanation as to why I was left out this time, although I haven't spoken to anyone at England. It's just one of those things. We haven't got that long off in the summer anyway so you just have to take the positives out of it. I'll get a good rest and come back next season raring to go."

Scott Brown hoped the bulk of the Celtic squad would stick around for next season, but felt keeping both the manager and striker Gary Hooper would be key. "People might leave and people might come in but the main thing, I think, is that we can keep the gaffer and Hoops as well," said the Celtic captain. "I think those are the priorities. Hoops showed [on Sunday] with the goals he scored and the way he played, just how good a striker he is."