Asked if he would be heading back to Manchester at the end of the season, Januzaj replied : “I don’t know.
“I wanted to join somewhere I could play and there were a few things behind that were a problem but I’m happy here. I just need more games to play and then I’ll be fine.”
The United forward made four starts for The Reds in August, scoring the winner at Aston Villa, before he left for Germany.
Januzaj joined a club brimming with slick forwards and he has been unable to barge ahead of Marco Reus, Henrikh Mkhitaryan and former United playmaker Shinji Kagawa in the Dortmund pecking order.
The PAOK game was only his third start for Dortmund and Januzaj has become such a peripheral figure at the Westfalenstadion he is in danger of missing the cut for Belgium's Euro 2016 squad.
Januzaj's fitness levels have also generated criticism in Germany and he conceded he was not in peak condition.
“I’m trying to do my best because obviously I’ve not got a lot of games in my legs which is difficult for me mentally, because I need more games to be a better player,” he said.
“Also at the moment i don’t really have that level of fitness that allows me to do more than another player.
“Of course it’s about adapting but I need more games to be fitter and take people on. I have qualities also that I showed in the first year in United but I need games in my legs which is difficult at the minute.
“But I’m training for myself and training hard to always be fit whenever l play so I can do something.”