Mertens revealed he has spoken several times with his international colleague about the switch and claims Napoli coach Rafael Benitez has also asked him to tempt Vermaelen.
"I have already told Vermaelen to come to Napoli 10 times," he told Belgian newspaper Knack.
"The city is magnificent and even Benitez asked me to convince Vermaelen to come here.
"But Arsenal is a great club and it won't be so easy for him to leave."
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