Mehmed Bazdarevic, manager of Bosnia-Herzegovina, had clearly done his homework. Recordings of Ireland’s recent visit to Warsaw would have revealed a fragile Irish left-flank, that crumbled in the face of Polish probing to deny Ireland automatic passage to next summer’s European Championship finals in France.

On Friday night, the personnel comprising that Irish left-side may have been completely different, but the vulnerability was just as marked. John O’Shea, who, along with Robbie Brady, made up the calamitous left-hand side of the Irish defence that night in Warsaw, missed out here through suspension. Ciarán Clark was drafted in to partner Richard Keogh and replace the Irish captain, with Stephen Ward also restored to the side at left-back. Robbie Brady moved forward to the left of midfield in place of the benched James McClean.

Ward’s performance on the night implied that his strong showing at home to Germany in October was a mere aberration. The target painted on the Burnley reserve’s back was almost visible, as the the Bosnians continually directed the flow of their possession down his side. All five of the host’s first half efforts on Darren Randolph’s goal originated from that flank, with right-winger, Edin Visca, the primary chance-creator.

It was Visca’s cross – and Clark’s clearance behind – that led to their only clear-cut opportunity of the half, when left-back Zukanovic directed a free header off-target from a Pjanic corner. Luckily for the visitors, the other three members of their rearguard performed admirably, contributing countless key interceptions and clearances to repel the seemingly never-ending stream of right-wing crosses. Richard Keogh, he of Championship side Derby County (and a perpetually haunted-looking visage) was particularly to the fore in that regard.

Contributing to the ease with which Bosnia worked the ball to Visca was Martin O’Neill’s choice of shape and personnel on the night. Since the home game against Scotland, the Irish boss had decided upon a narrow 4-3-1-2 shape as the best way of accommodating the craft of Wes Hoolahan – safe in the knowledge that the number ten would have three central midfielders behind him to do his running.

It was notable that O’Neill switched to a 4-1-4-1 system away to Poland, in the injury-enforced absence of Hoolahan. However, on Friday night, although the Norwich midfielder was again available, Ireland were faced with a paucity of strikers to fill the front two slots – thanks to the injury sustained by Shane Long and the suspension of Jonathan Walters. As a result, rather than start Robbie Keane  – a passenger in general play these days – O’Neill plumped for a 4-4-1-1 shape, with Hoolahan in behind Daryl Murphy.

The result was that Ireland struggled to stop the ball being worked from back to front easily by their hosts. Although the strategy was to allow the Bosnians to have the ball in their own half before confronting them at the halfway line, Ireland’s pressing in midfield was poor. Despite Bazdarevic springing a surprise on his nation by selecting a 4-4-2, Ireland were not able to use their extra man in the middle to their advantage and crowd out the Bosnian duo of Miralem Pjanic and the defender-by-trade, Edin Cocalic.

Hoolahan’s energetic performance off the ball against the Germans was in stark contrast to his defensive non-contribution here. Nor was he capable of providing the legs to assist Murphy in chasing down the endless clearances that were launched in his general direction. It’s hard to imagine Wes getting on the end of the long ball that his replacement in the number ten slot, Robbie Brady, collected to put Ireland ahead in the tie.

Ireland’s left-sided woes continued in the second half, with both Clark and Keogh called upon to contribute two vital interceptions in quick succession from Visca crosses early on. Ward, already in the book for a foul on the winger, saw his day prematurely come to an end soon after a foul on replacement right-full Vranjes, that could – and perhaps should – have seen him penalised with a second yellow.

In truth, referee Felix Brych – renowned for his usually card-happy nature – was extremely lenient in general on Friday night, with both James McCarthy and Edin Dzeko very fortunate not to incur yellow cards that would see them miss out through suspension on Monday night.

Yet, despite Ward’s substitution, the inevitable Bosnian goal, emanating from the right-flank, arrived. Substitute, James McClean, proved himself to represent no better protection for his full-back than Robbie Brady had, by allowing Vranjes to run off him and cross for Dzeko to finish – the first time in the game that the Roma striker beat the Irish defence to one of those deliveries.

Relief for Bosnia, who finally saw their direct, left-back targeting, strategy bear fruit right at the death. Bazdarevic has taken some stick in their media for the decision to forego a fifth midfielder, in favour of starting Ibisevic and Dzeko up top together – particularly given the fact that playmaker, Pjanic, was stuck deep initiating attacks from between his two centre-backs rather than operating in between the lines where Ireland looked potentially very vulnerable. Removing Visca at a time when he was causing havoc on his side’s behalf was also a very curious decision indeed.

As for Martin O’Neill, one wonders if he will revert to his now-favoured 4-3-1-2 formation on Monday, with Jonathan Walters available again to partner Murphy up top. One suspects that this decision will depend on the availability of Hoolahan to fill the number ten role, with the midfielder showing himself unable or unwilling to compete in two games scheduled so close together in the past. One thing’s for sure – now that the fog of war, both literal and figurative – has lifted, any uncertainty about the highly-touted capabilities of Bosnia-Herzegovina has been decisively razed. This is a battle that the Irish can very much win.