Aleksandar Mitrovic ready to quit Newcastle after being overlooked by Rafa Benitez
Mitrovic, sidelined with a back injury, spoke about his future in an interview with the Gazette last month.
The Serbia international is frustrated after only making a handful of Premier League appearances this season.
Mitrovic – who needs to be playing regularly ahead of next summer's World Cup – has opened up again in an interview with Serbian sports daily Zurnal.
United manager Rafa Benitez, however, will not let the 23-year-old leave in the January window unless he can secure a replacement.
"I persistently waited for the chance over the past months and I did not get it," said Mitrovic.
"I'm sorry – after all, I loved Newcastle, but it's time for me to look more to myself, to find the best solution for my career.
"I tried to be honest with myself and my team-mates at every training and match. And the fact that I did not get a chance is simply not up to me.
"I never felt better. I'm physically in flawless form. I cannot wait to play. The most important thing is to find a club and finally get a chance in the field."
Mitrovic is behind Dwight Gayle and Joselu in the pecking order at Newcastle, who take on Manchester City at St James's Park tonight.