The Manchester United boss was impressed with the Red Devils’ season opener against West Ham last week.
They crushed the east London outfit 4-0 with debutant Romelu Lukaku scoring a brace.
While it was a dominant display, Mourinho feels his side can still improve.
And he has urged them to continue with their happy football as they take on Swansea at the Liberty Stadium.
“The team is quite stable, the team is playing happy football”
He told Sky Sports: “Of course we can improve.
“Every match is a different match.
“You are never in control of matches for 90 minutes.
“I can expect, that even if we are team playing the tactical discipline like we do, there will be for sure moments in the match where we will not have this control and we need to keep our stability.
“The team is quite stable, the team is playing happy football.
“I like to call it that because the players are very comfortable on the pitch and we have to try to have a good performance because only with a good performance can we beat a team that is a good team.
“For sure they [Swansea] have the ambition to start well in front of their crowd.
“What is happy football? I think a little bit more freedom instead of too much connected with the tactical discipline that we need, and we always need, but we also need this happiness, this freedom to want the ball, to want to participate.
“To open passing lines, to try and influence the game, players without fear to move, without fear to go into areas that are not in the tactical design.
“I am confident we can do that we have to respect them when they have the ball and we are going to try to do that.”