Michael Stewart: 'Celtic need seriously deep pockets to fix problems & clock is ticking'

It was never a case of if Neil Lennon would leave Celtic but when. His eventual resignation on Wednesday carried an air of inevitability.

'Too late' was the cry in regards to this season. And, the longer Lennon was left in place, with the club knowing he would not continue next term, the more it affected their plans for the new campaign.

The Celtic manager's role is an absolutely massive job, a colossal job.

A new boss will have something of a clean slate given the number of players likely to move on, but upheaval behind the scenes, a change in chief executive, and potential restructuring, is unattractive to candidates.

Celtic are not yet a well-oiled machine. It will take a lot of time and effort, and seriously deep pockets, to rectify.

Big-name boss or young, hungry prospect?

So, what and who should Celtic go for? There are two distinct paths facing the club's decision-makers: a big-name manager who would relish the challenge, as Brendan Rodgers did, but might only hang around for a couple of years.

Or someone younger and hungry who wants to build something longer-term but carries more risk through their lack of experience.

Rafa Benitez has done some incredible work. To land him, it would probably take principal shareholder Dermot Desmond pulling out the stops and saying, 'What do you want? Right, there you go.'

• Lennon resigns as Celtic manager

• 'Lennon's successes will outlive all of us'

• McKay won't join Celtic early

• The key games that ended Lennon's reign

Like any top name, he would look for assurances and guarantees. But he might view Celtic as a place to enjoy himself, finish his career and sail off into the sunset.

Frank Lampard is young and relatively inexperienced, but I think he'd be looking at Celtic as an opportunity to move back down south fairly quickly.

I'm loath to bring up Steve Clarke, but it's inevitable he will be discussed. Kilmarnock were in dire straits when he took over at Rugby Park and he did a phenomenal job.

He's been successful with Scotland as well and not only do the Euros finish days before Celtic's first prospective Champions League qualifier but the World Cup is only next year. That would certainly help entice Clarke to stay put, but I would imagine Celtic will definitely look to speak to him.

'Rodgers' success masked issues behind scenes'

Whoever Celtic appoint, they need to address what seems to be a huge lack of synergy within the departments at the club.

The prolific success of the Rodgers era masked some of those issues. Certain players were signed and we don't know if they were the manager's choice, but it didn't stop them winning everything. Now, those cracks have been magnified.

Gone are the days when a manager was in sole charge of recruiting players, doing the contracts, bringing them in. It has to be a collective and that collective has broken down. Those doing the recruiting have not been good enough.

When Celtic blew the chance to sign Fraser Forster and messed Craig Gordon about, Vasilis Barkas was brought in as goalkeeper. Shane Duffy has been a disaster in defence. Albian Ajeti has not worked up front.

There have been panic buys. Who decided to sign left-back Diego Laxalt on loan? He's no better than Greg Taylor and he undermines the player you have paid for and contracted. The thought process is clearly just a short-term desperation for 10-in-a-row.

The person who is ultimately saying 'yay' or 'nay' has got it wrong, so you question their judgement.

There seems to be a complete disconnect between what the manager is looking for and who is brought in. You cannot have that. You have to be pulling in the same direction, delivering evidence and action, not soundbites and empty rhetoric.

Celtic are reportedly keen to hire a sporting director. As an outline title, someone who focuses on dealing with transfers and recruitment, I don't think it's a bad thing, but there has to be a clear line of authority as to whether the manager is working above or beneath the sporting director.

The manager is the guy who will be dealing with the players; he has got to have the veto when it comes to the crunch.

So much needs to be sorted out at Celtic on so many fronts. Long-standing chief executive Peter Lawwell is leaving, with Dominic McKay coming in from Scottish Rugby. McKay has never worked in football; has he ever done a transfer?

Will recruitment specialist and head of football operations Nick Hammond be given a stronger position? There are question marks over whether he should have a position at all if he is behind the signings made these past few years.

Players will leave - some will want to go, others are out of contract or reaching the end of loan spells and others still will be moved on by the club. There is going to be a big turnover.

Season tickets will be on sale soon and all of these things are clearly going to be weighing on the board. The clock is ticking.

Former Scotland midfielder Michael Stewart was speaking to BBC Sport's Jamie Lyall