United have long been linked with a move for the Belgium international.
“I know that Manchester United are closely monitoring my situation. There hasn’t been any official contact yet though,” said Defour to Extra Time.
“I’ve been sidelined for quite a while due to injury, but I’m playing at a high level again. The chance that I’ll leave the club is rather big if I continue to play like I currently do.
“I’ve had the opportunity to leave Standard on more than once occasion in the past couple of seasons, but I loved the club too much to leave. However, I’m 22 years old now and I also have to think about myself.
“There comes a time when you just have to make the next step in your career, regardless of sentiments for any club.”