Carlo Ancelotti believes Jose Mourinho can make an immediate impact at Manchester United and quickly restore the club to the top of English football.
Mourinho is expected to sign a deal to succeed Louis van Gaal by Thursday and will be tasked with lifting the 13-time Premier League champions after their fifth-place finish last season.
Saturday's FA Cup win over Crystal Palace was United's first silverware in the post-Sir Alex Ferguson era, but Mourinho's targets will be much higher and Ancelotti, who is to succeed Pep Guardiola as Bayern Munich manager this summer, says Mourinho to Old Trafford is a good fit for both parties.
"It is a fantastic challenge for both sides," he told Sky Sports News HQ. "Mourinho is one of the best managers in the world. He has good experience of the Premier League and Manchester United needs this kind of manager."
Ancelotti is looking forward to watching the next chapter of the Mourinho-Guardiola rivalry from Germany after the pair clashed during their time at Real Madrid and Barcelona respectively.
"It will be exciting to have two of the best managers in Manchester," he added. "It will be fantastic. It will be exciting."
Ancelotti had words of support for Van Gaal, saying the Dutchman was still having to deal with the loss of both Ferguson and several senior players.
"Van Gaal's job was not bad," he added. "It was not easy after Ferguson left and top players like [Rio] Ferdinand, [Paul] Scholes and [Ryan] Giggs to rebuild the team. He did a good job, but Mourinho and United could be good for both."