The Honduran has come in for plenty of criticism of late. And it seems more than justified.
Only last weekend, Celtic fans were, not for the first time, expressing their frustration with Emilio Izaguirre.
It probably came as no surprise to them, then, that it was the 29-year-old left-back who conceded the penalty that condemned the Scottish champions to a 2-2 draw at Kilmarnock on Wednesday night.
It could happen to anyone, of course, and mistakes are made by the best of the best. Consistent flaws, though, are a different issue. And consistent flaws that go unaddressed are even worse.
Indeed, Celtic fans have been concerned about Izaguirre for quite some time. In the Bhoys' current system, there is a lot of emphasis on that left-back role. Izaguirre must be able to cross well - and a lot - something he doesn't quite seem capable of right now.
He must also be able to get back and defend in equal measure. In both regards, the 29-year-old can be considered Celtic's weak link.
Ronny Deila is a loyal backer of his players, of course, as his continued support for the likes of James Forrest has shown. The Norwegian was even lenient with John Guidetti last season, despite the fact many have judged the young Swede's antics as nothing more than petulant once he lost his place in the Celtic first team.
Could now be the time to put loyalty aside, though, and sign a new left-back - making it clear to Izaguirre that only a place on the bench will do if he isn't up to scratch?
After all, one weak link can be the difference at the most crucial stages of the season; especially in the Champions League.