"I think after this match that is the best route (into the Champions League and that is not so easy because there are a lot of very good teams participating in this event (the Europa League)," he said on BT Sport.
When questioned on how disappointing the defeat was, the under-pressure Dutchman said: "I think what I said before the game, you have to win these kind of games and we didn't and we can only blame ourselves.
"Two goals from two set-pieces. They had more aggression than us and we could not cope with that aggression and we don't keep the ball in our possession".
Sunderland boss Allardyce said: "I think the game was similar to (Manchester) City but this time we got what we deserved. The chances we created and the clear-cut one we had was worrying me because we should have been 2-0 up.
"N'Doye was through one-on-one and I was wondering if it would go for us but luckily our new boys helped us out today and it's an unbelievable result for us, beating Manchester United but beating them in the position we're in. This is three big, big bonus points for us".
- Telegraph