Guardiola dumped the Swedish superstar from Camp Nou back in 2011 and it is clear to see that the Zlatan has not forgotten.
Ahead of Saturday's derby clash at Old Trafford, the 34-year-old striker said: "Mourinho's direct with everyone.
"He's not a coach that goes behind your back.
"He will tell you. If you're not good enough, you're not good enough.
"I prefer that it's like that instead of having somebody that doesn't say anything to you. But you think it's good because you don't hear anything."