Wayne Rooney came off the bench to rescue an injury-time equaliser for the Red Devils this afternoon, in the process scoring his 250th goal for United to become the club's all-time leading goalscorer.
The result extended United's impressive unbeaten run to 17 games in all competitions, but speaking afterwards, Mourinho said that he was "not happy" at his side registering their eighth draw of the campaign.
"I don't know if I can call it rescuing a point when we dominated for 70 mins and created chance after chance," he told BBC Sport. "[David] de Gea doesn't make a save. I don't even know if I am happy because I am not happy. We played well enough to win the match. Sometimes it is important when you miss so many chances.
"I think [Marcus] Rashford and [Jesse] Lingard helped to give the team a different dynamic. I don't know how we missed so many chances. We work a lot but the reality is we are very offensive but don't score enough goals. We have too many draws. It is easy to say we deserve to win these but we need to score.
"We missed unbelievable chances. We hit the post, the keeper saves, we miss chances and we have another draw. We have too many draws for the attacking play we produce. Opposition goalkeepers are always amazing against us."
The result left United sixth in the Premier League table, three points off fourth-placed Arsenal, who have a game in hand.