Ronald de Boer responds to Mourinho’s savage put down of his twin

Jose Mourinho has engaged in more than his fair share of wars of words in his time but his putdown of Frank de Boer on Monday was particularly vicious.

Mourinho slammed De Boer as the "worst manager in the history of the Premier League" following the Dutchman's remarks about Marcus Rashford's development under the Manchester United manager. Rashford started and scored both of his side's goals in United's 2-1 victory over Liverpool on Saturday but De Boer claimed that it is a "pity" that the young forward is going through his formative footballing years under Mourinho. That prompted a furious reaction from the Red Devils boss as he mocked De Boer's ill-fated spell in charge of Crystal Palace. "If he [Rashford] was coached by Frank, he would learn how to lose because he lost every game," Mourinho said. 24 hours after one of the most brutal managerial insults, De Boer's twin brother Ronald has tried to play peacemaker as he insisted that Frank has the utmost respect for Mourinho. "Managers have different philosophies when developing young talents," Ronald de Boer, who is academy team manager at Ajax, told Sky Sports. "Not right or wrong, simply different, and you have to respect that. "Mourinho has bought (Alexis) Sanchez in January and of course it's the truth that it's not good for Rashford's development and he will play less now for Man United. "Rashford is without doubt one of the biggest talents in the Premier League and could play a big part in Russia (at the World Cup) this summer. "Frank respects Jose a lot and was simply pointing out that, if Rashford was playing for Ajax and had one or two bad games, he would still start the third game. "However, he's at Man United and after two bad games things are different and he'd be on the bench."