Jozo Simunovic and Kristoffer Ajer rise to defend Celtic's honour

There was a temptation to offer up the old '˜good luck with that' line over Brendan Rodgers' pre-match targeting of a clean sheet last night. Cynicism about the potential of a shut-out was far from entirely wrapped up in the frailties exhibited by Celtic in defence across recent times.

Celtic's Jozo Simunovic holds off Zenit's Emiliano Rigoni. Picture: Craig Foy/SNS

Certainly, the need for the Irishman to select a backline triangle of goalkeeper Dorus de Vries, and centre-backs Jozo Simunovic and Kristoffer Ajer could inspire no great confidence. The trio had never played together in continental competition before. Moreover, in all-too-many of his appearances in recent months, Simunovic hasn’t looked like a pivot capable of playing without putting his own team in grave peril. Paired up with 19-year-old Ajer, the thinking was that if Partick Thistle could give the duo difficult moments, Zenit St Petersburg would provide a whole heap more.

Yet, the absence of optimism over what might ensue for Celtic defensively in last night’s Europa League last-32 tie couldn’t all be laid at the door of the trio.

In European competition proper – that is, outside of qualifiers – Celtic hadn’t kept a clean sheet at home since 3 October 2014, when they rode their luck to claim a 1-0 over Croatia Zagreb in the Europa League group stages.

Even with a future £75 million defender in Virgil van Dijk and, later, with first picks that Rodgers would have selected over Simunovic/Ajer, Celtic haven’t been able to repel the advances of continental visitors to the east end of Glasgow. In addition, of the four knock-out stage games in European competition they have contested since group stage football was introduced almost three decades ago, they had only once achieved a clean sheet in a home first leg – remarkably, looking back, it was against AC Milan in the last 16 of the Champions League in 2007.

In the Rodgers’ era, the commitment to playing on the front foot against Europe’s elite has left them open to being picked off. Roberto Mancini’s Zenit side may not belong in that bracket, but the club with a £77m spend on players in the past year were expected to be good enough to exploit Celtic’s backline weaknesses. Even if they had last played competitively on 11 December owing to their winter shutdown, which came after they had been top scorers in the Europa League group stage with 18 goals.

That for so much of the encounter the charmed life enjoyed was by the players in front of the Zenit goal wasn’t just owed to Simunovic, in the general, and Ajer, in particular rising to the occasion. It was also in no small part to the fact that Rodgers ensured there was greater protection in front of them.

The Irishman had seemed almost downbeat about his team’s prospects in the lead-up to the tie. Gone was the bullishness about adapting or curtailing expansive instincts in an environment that has proved unforgiving over such noble intentions this season. In its place was an element of pragmatism, with Eboue Kouassi effectively fielded as a third midfielder alongside Scott Brown and Olivier Ntcham, with Callum McGregor pushed further forward as essentially a disguised No 9.

Tactically, Rodgers was vindicated in all his alterations. Celtic dominated in the centre of the park – where Ntcham was a powerhouse – and the solidity of the defence had the effect of allowing them to attack their opponents relentlessly. Defensively then, Celtic were never under sustained pressure but that should take nothing away from the maturity and controlled aggression that made Ajer such an immense figure and that sinew-straining efforts from his defensive colleagues Simunovic, Kieran Tierney and Mikael Lustig that made Celtic impenetrable. It gives them hope for next week’s second leg after it was expected that there would be no case for the defence in St Petersburg.