The Dane hired Sanchez at the beginning of December last year in a bid to help her secure the grand slam title that has so far eluded her.
However, the 21-year-old was beaten in the quarter-finals of the recent Australian Open by Kim Clijsters and surrendered her world number one ranking in the process.
Wozniacki now finds herself down in fourth spot behind Maria Sharapova, Petra Kvitova and, Australian Open champion, Victoria Azarenka.
Wozniacki will now go back to being solely coached by her father Piotr who told Danish newspaper Ekstra Bladet that his daughter had split from Sanchez because she was not getting any "new impulses" from the relationship.
However, Sanchez has claimed that the continued involvement of her father during his time with Wozniacki was one of the reasons the partnership had worked.
He insisted he found it "impossible" to have a system with two coaches and said that, "Caroline only got confused."
"Piotr has his system, I have mine," added Sanchez.