Alexander Zverev has expressed an interest in working with fellow German Boris Becker, but says the six-time Grand Slam champion would cost more than he could pay at the moment.

The 19-year-old, currently the youngest player in the Top 50, took Rafael Nadal to five sets in the third round of the Australian Open. He is currently coached by his father and helped by his brother, fellow ATP pro Mischa, but is looking to keep moving up the rankings

"Boris could definitely help me to improve my game," he told German newspaper Bild. "But if I want to work with him, first I have to win some tournaments, because at the moment I cannot afford it."

Becker stopped coaching Novak Djokovic following the ATP Tour Finals in November, and is now again doing commentary, working for Eurosport. He had indicated that he would be interested in coaching another player. Speaking to Belgian reporters during Germany's Davis Cup tie against Belgium, he described Zverev as "a talent," but noted that he had "not won anything extraordinary."

Zverev is No. 21 in the rankings.