The 20 year-old Dutch attacker has joined Lazio on a four-year contract in a Bosman deal.
“I would go train at Liverpool with the firsts, but after that I would play in the Under-23s again.
"I didn't like that, so I decided to leave," he said.
"A number of clubs were interested, but I will not comment on that. I don't think that is a good thing for Lazio. That is all behind me now."