Away goal means Ireland are walking a tightrope

It is a rule that has tipped the scales of European football for exactly 50 years, has the potential to make every minute of tonight’s 90 feel insufferably heavy, but only offers a benefit that Martin O’Neill says can be “wiped out” in a second.

Ireland might have the advantage of ‘the crucial away goal’ from the 1-1 first leg in Zenica but one slip, one error, and Bosnia and Herzegovina would suddenly have the platform - and possibly the confidence - to go and get a second such strike themselves.

So much worry, then, over so potentially small a moment.