Nike signed Amanda Anisimova, the American tennis player, to an endorsement contract that may be among the largest ever signed by a teenager, according to the New York Post.

Anisimova, who was born to Russian parents and is based in Florida, is ranked 21 in the world after a breakthrough year in which she reached the fourth round at the Australian Open and the French Open semi-finals.

The deal is similar to Maria Sharapova’s eight-year agreement with Nike which ends this year, sources told the New York Post. Sharapova is soon to finish up an eight-year Nike deal worth $70 million.