Belgian legend Franky Van der Elst has slammed Genk's leaky defence ahead of their Europa League opening game against Rangers this week.
Rangers start their league phase campaign with a visit from the Belgian side on Thursday.
Like Rangers, they have had a disappointing start to the season and their supporters have been voicing their displeasure after they slumped to tenth place in the table.
And 86-times capped Belgian ace Van der Elst - who played in four World Cups for his country - has been alarmed at their defensive efforts ahead of their trip to Glasgow.
He said: "What amazes me about Genk is that they have failed to keep a clean sheet in their last 16 matches ahead of this weekend.
"And if you add in their two European matches against Lech Poznan, that's 18 matches without a clean sheet.
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"That's nowhere near good enough.
"They had collected eight points out of a possible 21 and that is unacceptable for them.
"Genk's problem is that they are vulnerable when teams counter-attack.
"And they seem to be unable to defend crosses into the box.
"I happen to think Thorsten Fink is a fantastic manager for Genk
"But I believe he also needs to be firmer and more assertive with his players for not performing."
