Dutch midfielder Wesley Sneijder admitted that while he enjoyed working with Louis van Gaal when it came to football, the pair could not see eye to eye on a personal level.
Sneijder worked with Van Gaal at Ajax in his early days before reuniting with the latter in 2012 with the Netherlands national team.
Despite repeatedly praising the coach for his tactical nous, the same could not be said on an interpersonal level.
"I have always said that Van Gaal is the best coach there is, technically and tactically," Sneijder told Fox Sports.
"There is no better coach than Van Gaal.
"But I think there is room for improvement when you look at the way he deals with his players and staff.
"I had a perfect time with him on the pitch, as a coach, because his training sessions were the most fun.
"But as a human being, I have had nothing but trouble with him on a personal level."