Van Gaal, 62, finally started work as United boss this week having led the Netherlands to the semi-finals of the World Cup this summer, and will be expected to improve massively on the disaster that was the David Moyes era. The former Ajax, Barcelona, Bayern Munich boss will be pitting his wits against Mourinho next season, but that doesn't mean the two are total enemies.
During van Gaal's time at Barcelona, Mourinho was on the coaching staff at the Camp Nou and learnt a large amount of his tactical nous under the Dutchman. The pair faced off against each other in the Champions League final in 2010, and they can expect to see more of each other in the coming seasons - and whilst Mourinho says he has great respect for van Gaal, he isn't afraid of him.
"I'm not worried about him being here. I look forward to playing against United. Nothing worries me," said Mourinho. "I watched him at his press conference and he was pure Van Gaal - honest and open, the way he always is. He is a very, very good coach, he'll be great for Manchester United."
"We are both great coaches. It's what we were born to do," added Mourinho. "Louis was the best coach in the World Cup and he is a good friend - really, a friend for life. I have deep respect for this man. He is in the best period of his career. With coaching, if you deal with winning and losing in the right way, you improve. He analyses every experience. He has got better and better."
Van Gaal's United play host to Chelsea on the 26th of October this season, signifying the first meeting of the two managers in the Premier League, before Mourinho's Blues welcome van Gaal and United to Stamford Bridge on April 18th.