Manchester United fans welcomed Jose Mourinho to Old Trafford on Sunday. Getty Images

Manchester United manager Jose Mourinho says he is "happy and involved" in the beginning stages of his Old Trafford tenure.

Mourinho, who was a spectator in the stands for the Soccer Aid charity match at Old Trafford on Sunday, was hired to succeed Louis van Gaal as coach last month after two disappointing seasons under the Dutchman.

Mourinho, who had been initially expected to manage one of the teams, apologised for not being more involved in proceedings on the night, citing his work with United as a reason for his unavailability, while also describing Old Trafford as his "house."

Mourinho, whose presence in the stands was the first time the Portuguese had appeared at Old Trafford since being appointed as the new United manager, said: "I'm sorry I couldn't be more involved tonight and I was sorry not to enjoy training with the England boys this week, but I am so happy and involved at beginning my job at Manchester United that all the time I have right now is working time.

"I want to be part of it, and I will be, from the stands. I will be another one contributing to such a memorable day. I want to enjoy the game at my house, Old Trafford."

Mourinho was seen beaming in his seat during Sunday's charity match -- his first visit to Old Trafford since being hired. PA Sport

Mourinho's coaching duties were passed on to Sunderland manager Sam Allardyce who led out the side, with Leicester City's title-winning manager Claudio Ranieri in charge of the opposition team. The United manager was often spotted beaming, as he looked on in his new, regular surroundings.

Before the match had started, Mourinho had walked into Old Trafford appearing relaxed, dressed in blue shirt and blazer with jeans. There was then a picture posted of him in the tunnel for the first time, surveying his new surroundings, with the United badge on the wall visible.

During the game, there were some chants in support of him from the crowd and a sign held up saying "Welcome to Old Trafford, Jose."

There was a strong United presence on the team sheet for the match, with Phil Neville, Jaap Stam and Dimitar Berbatov all involved. There were also appearances by World Cup winners Ronaldinho, Cafu and Fabio Cannavaro. Pele was the guest of honour and shook hands with the teams before kick-off.