The Red Devils were held at Old Trafford by Everton last night, with Zlatan Ibrahimovic rescuing Mourinho's men with a late penalty.
United have drawn nine of their 16 home games this season under the Special One.
The Red Devils now face a serious battle to finish in the top four - with United currently in fifth place, four points behind Manchester City in fourth.
And Mourinho has opened up on his side securing Champions League football, claiming it all depends on United's rivals.
"More difficult, very difficult," said Mourinho.
"It is mathematically possible but depends on our opponents.
"It is an amazing run of 20 matches unbeaten but too many draws at home. Because of that we are in the position we are.
"We build well but we don't score enough goals, we don't kill off enough opponents and at the end of this season I think we will be punished by that."
