Cape Town - Manchester United boss Jose Mourinho remains the best coach in the world and not his Man City rival Pep Guardiola, claims Middlesbrough manager Aitor Karanka.
Mourinho and Guardiola both took the reins at their respective clubs at the start of the season and Karanka believes the Red Devils made the better choice.
Karanka's Middlesbrough faces Man City in the FA Cup quarter-finals and during his pre-match press conference, the Spaniard spoke highly of the former Chelsea boss.
"Pep is not the best coach in the world. The best coach in the world is Jose Mourinho," Karanka said.
"He has shown it at Porto, at Inter Milan, Chelsea and Real Madrid and Manchester United. He was the best [in La Liga] and he still is the best.
"I've never worked with Pep, but Jose started this season with some criticism, but he has already won two trophies for Man United.
"Jose is the best for me. I think Pep has to win the Premier League to prove [he is one of the best]. I think he has to win a trophy [this season]."
Karanka, who was Mourinho's assistant during their time at Real Madrid, believes Guardiola will take time to adjust to life in the Premier League, while his former boss has plenty of experience managing in England.
"I think he's [Guardiola] realised that this is a different football, a different league, and he has grasped how difficult the challenge is. It's taking him time to adapt and it's not been easy for him," he said.
"It's difficult when you arrive in a new country, with a new philosophy where a lot of things are different.
"He has some very good players, but the mentality here is different. Things are different and it takes time to adjust."