Zlatan Ibrahimovic squandered United's best opportunity when he miscued a second-half header from a Pogba cross as the visitors were restricted to just one shot on target over the 90 minutes.
"Had it been 1-0, it would have been finished," Mourinho told Sky Sports.
"Where Pogba was playing, I was expecting more penetration.
"Defensively we did really well, we should have had a little bit more. We had a big chance that I thought Zlatan was going to score."