Jose Mourinho has been "very humble" at Manchester United from the start of his reign and even sent a good luck message to Sergio Romero, the reserve goalkeeper has told ESPN FC Radio in Argentina.

Former Chelsea manager Mourinho announced himself as a "special one" when he arrived in London in 2004, but Romero has seen a more caring side to the 53-year-old in Manchester.

"He is not a very complicated person. He's been very humble from day one," Romero said. "I didn't know him and he sent me a message saying that he wished the best for me at the Copa [America in June] and with the national team.

"He keeps track of everything. I saw that here. It's true that he demands respect from a person but then he gives them free rein to work. He takes the pressure away so that you can work without stress.

Sergio Romero could find more playing time this season with Man United in the Europa League. Matthew Ashton/AMA/Getty Images

"In the short time he's been here, he has shown us his tactical way of working and now we are already seeing a different Manchester United. The team has changed a lot."

Romero is behind United's first-choice goalkeeper David De Gea in the pecking order, but a busy schedule, including participation in the Europa League, could open the door for more game time.

The former Sampdoria goalkeeper made 10 appearances for United last season and 12 for his country including the Copa America, when Argentina lost the final on penalties.

The 29-year-old said: "I hope that this season is better than the last. I hope to play more with my club and to help the national team get to Russia [for the World Cup] in the best way possible."