He claimed he was being left out of decision-making.
“From next year, I will no longer follow Rafael on the circuit and I will focus exclusively on our (tennis) academy,” he was quoted as saying on the Italian website tennisitaliano.it.
“Relations with my nephew are still excellent. During all these years, we have never been through a crisis.
“Until he was 17 years old, it was me who decided everything. Then Carlos Costa arrived as manager. Then his father became closer, each having his opinions.
“And the truth is that every year I had less decision-making, until the day when I will decide on nothing.”
Carlos Moya joined the Nadal coaching team at the end of last year.
Nadal recently lost in the final of the Australian Open to Roger Federer.