Ajax youth academy coach Ronald de Boer has claimed that on-loan Arsenal striker Yaya Sanogo has "no qualities" to offer the team.
The 22-year-old frontman joined the Eredivisie side last month on a season-long loan deal and scored a hat-trick in his first start for them on Monday, as they beat Qatari side Umm Salal 6-1 in a friendly.
Ajax manager Frank de Boer has backed Sanogo to shine in the Netherlands, but twin brother Ronald has admitted that he is not sure what the Frenchman has to offer.
"I heard Frank say last week that this is one of the best squads with whom he has ever worked," he wrote in Voetbal International.
"However, when I see Sanogo, I still have my doubts. I have still found no qualities with which you can do something.
"I think that Ajax has too little depth, the real speed is lacking, meaning that your opponent can never be surprised. An opponent of Ajax can therefore cope quite easily under pressure and that makes the team relatively easy to defend against."
Sanogo has scored once in 19 appearances for Arsenal in all competitions.