Copenhagen: Women's World Number One tennis player Caroline Wozniacki of Denmark has employed Spain's Ricardo Sanchez as her full-time coach.

"Richi (Ricardo Sanchez) will be in charge of practical matters. He is good at doing those things which need to be done during training," Wozniacki said.

"He has many years' experience coaching different players, he is a very positive person," she added.

Wozniacki, 21, finished 2011 at the top of the rankings for the second year running, but has never won a grand slam title in her career.

Sanchez predicts Wozniacki has several grand slam victories ahead of her.

"She will win (grand) slams. She is ambitious. In (grand) slams you need luck, but Piotr (Wozniacki) and I have discussed that she must be a 'tennis-machine.' It should not just be about luck," Sanchez said.

"If she improves 30 percent, she will get so much self-confidence that she will play in a more relaxed way at grand slams," he added.

Piotr Wozniacki is Caroline Wozniacki's father and former coach.

Wozniacki herself told Danish media on Wednesday that she will put all her efforts into winning a grand slam title and an Olympic Games medal in 2012.