Nicole Scherzinger's boyfriend is finding it ''difficult'' to balance their work schedules.

The former Pussycat Dolls singer has been dating tennis ace Grigor Dimitrov since late 2015 and, although their relationship is stronger than ever, the 27-year-old sportsman has admitted it can be tough trying to find time to see each other enough.

Speaking to OK! magazine, he said: ''I think both of our successes have come because we help each other. The long distance and our time schedules are difficult, but it is what it is. That's how things are at the moment.''

This isn't the first time the couple have commented on their long-distance love as Nicole, 39, admitted last year that life on the road can get quite ''lonely'' at time.

She said: ''Anybody who is successful in what they do is making sacrifices. It's juggling and finding the balance. I've absolutely missed out on things in life.

''It is hard, I'm not going to lie. It can be lonely. I'm always on the road, I'm always by myself. I think anybody in this industry feels lonely.

''I would say it generally gets harder to find the balance the older you get. Timing is everything. When things are aligned then it will be easier. There's always a sacrifice to be made but it's either worth it or not.

''For me, I'm very spiritual. What guides me the most is my purpose. Everything in it's own time and to start on track with my purpose. I've got a great support system around me, a select group of friends. I don't have quantity, that's for sure, I have quality. I've always been more introverted. Gratitude is key.''

Nicole was also quite resentful of her career a few months back because she hated the fact that she was still unmarried and didn't have any children.

She explained: ''Relationships suffer. I'm not married and I haven't got kids yet.''