CELTIC are in the midst of a crisis. On their worst run of form for a decade and with a record tenth consecutive Premiership title slipping from their grasp, the situation facing Neil Lennon is as just about as bad as any to have plagued any manager at the Parkhead club since the turn of the century.

Elimination from the Europa League has already been confirmed, the 35-game winning run in the cups spanning four seasons was brought to an abrupt halt by Ross County in Glasgow’s east end on Sunday and worst of all, they trail their rivals Rangers by 11 points around a third of the way through the Premiership campaign, albeit having played two fewer games.

The notion of Celtic missing out on 10 in a row seemed fanciful only a few years ago as Brendan Rodgers’ side brushed aside their domestic opponents with minimal fuss and regularly won the league at a canter, yet the prospect of the Premiership trophy making its way to Govan for the first time since 2011 is coming ever closer to being realised.

It has been quite the fall from grace for a side that appeared untouchable at the zenith of Scottish football, and the reality of Celtic’s decline is made all the more stark when we examine the team’s underlying data.

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The 2016/17 invincible campaign is the natural benchmark for Celtic managers to test themselves against and it’s only fair to mention that despite his side’s shortcomings this term, Lennon’s team were not far from hitting those dizzying heights once again last season in some ways. Rodgers’ team collected 2.79 points-per-game on average in the Premiership that season; in the previous one, Lennon’s men were picking up 2.67, the second-best return in each of the last six seasons.

This term, that figure has dropped once again and now sits at 2.3 points-per-game – which is still higher than Rodgers’ return during 2017/18 or 2018/19, and not far off the 2.36 Lennon was averaging when he replaced the former Liverpool boss at Parkhead for the remainder of the 2018/19 season – but when added to Celtic’s underwhelming displays in Europe, the shock exit in the Betfred Cup and the ominous form of their rivals across the city, we can see why the pressure is mounting on Lennon.

Despite the blunt and often laborious manner in which his team have attacked this season, Lennon’s front line is still not the worst seen at Celtic Park in recent years. They’re currently averaging 2.62 goals per game in all competitions – a figure only bettered by Rodgers’ invincible campaign (2.79) or the previous one under Lennon (2.97) – while their expected goals (xG) per 90 minutes sits at 2.14; still an improvement on Rodgers’ second season in charge but worse than each of the last five campaigns.

What this tells us is that while Celtic have clear problems when it comes to creating opportunities, relative to their own high standards, their goalscorers have actually been overperforming this term and have scored more than they ought to have, given the quality of chances they’ve been presented with. Yes, improving the club’s xG would be a welcome development but it is not the most urgent task to hand. The most pressing issue that needs resolved – quickly – can be found at the other end of the park.

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Celtic have tended to concede around 0.65 goals per Premiership game over the last five seasons, which works out at around two goals every three games. In Ronny Deila’s final season in charge, this figure spiked at 0.82 but decreased under Rodgers and again under Lennon, with Celtic shipping as little as 0.63 goals per game last season.

This year, that figure has skyrocketed to 1. That might not sound like a huge jump but that is a two-thirds increase on the previous season’s figure and amounts to an additional 14 goals against over the course of a 38-game season, should nothing change. Given that Celtic only conceded 19 goals in 30 league outings last term, we can see the strain that the current leaky defence are placing on their side’s chances of victory.

As bad as things have been at the back, there’s an argument to be made that Celtic have been getting off lightly. In the Premiership, their expected goals against (xGA) per 90 currently sits at 1.21 – nearly double last season’s rate of 0.63 – and is even higher than the 0.99 achieved by Deila in his final year.

What this tells us is that based on probability, Celtic should have conceded even more than they already have in the league this season and that in terms of both the quantity and quality of chances they’re affording the opposition, this is the club’s worst defensive unit in many years.

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Lennon’s exciting brand of free-flowing, counter-attacking football that replaced the smothering, methodical approach of his predecessor always meant that his team would cede control of the ball in favour of attacking swagger, something that was in stark contrast to Rodgers’ approach. When it worked it created one of the most exciting, fearsome and downright lethal attacking sides in the modern era in Scotland but it came at a price.

The defence has become ever slacker and now that things aren’t quite falling their way of Lennon’s players in the final third, this deficiency at the back is becoming increasingly apparent and costly. Unless things continue, and soon, it might just signal the end of Lennon’s second spell in charge of the club.