Now on-loan at Crystal Palace, Loftus-Cheek was best afield on his England debut in Friday's 0-0 draw with Germany.
Loftus-Cheek's father, Trevor, told the Daily Mail that he felt his son's development had been hampered while former Blues boss Mourinho was in the Stamford Bridge hotseat for a second spell between 2013 to 2015.
"Jose Mourinho held him back," said Loftus-Cheek's father. "He should have been playing.
"Everyone behind the scenes was asking: 'why isn't he playing?'"
He added: "If Ruben was playing for Mauricio Pochettino, he'd have 70, 80, 90 first team appearances by now."