However Ole Gunnar Solskjaer was left frustrated with United's finishing, and Rashford was the main culprit, with the manager saying, "How we didn't end up with five, six or seven, we don't know".
The full-back suffered ankle ligament damage in August that prevented him from making much of an impact during the early stages of the season.
He has since returned and Lampard has now welcomed competition in the full-back areas.
Excitement as Mercury passes in front of Sun today, Monday, November 11
Look at little Mercury go! The transit began at 12:35 GMT, when the edge of Mercury appeared to touch the edge of the Sun. Thirdly, Mercury starts to cross over the edge of the sun's disk that is at the near end of the transit.
However, the Chelsea legend says he's relishing the problems that could pose in regards to selection and has praised James for seizing his opportunity.
But shortly after his 79th-minute goal - his fifth goal in the last three Premier League games - Pulisic was subbed off with a hip injury.
When asked about informing Azpilicueta of his decision to play James, Lampard told reporters: "It's part of my job". It is actually a decision [I've made] when Azpilicueta is playing really well for us.
And the England global will be particularly annoyed at missing what was essentially an open goal, with the manager adding, "I don't know how he missed it and you're surprised when it doesn't go in".
"Azpi is such a great personality and character". He feels for the club and wants the best, that shows how much I value him now and going forward. It is a nice problem.
Kanye West might change his name to Christian Genius Billionaire Kanye West
We just move on, but we don't really talk about things that happened, and I don't really know if that's healthy or not. Him and I have our own relationship and then Tristan and True have theirs, and I will never come in between that.
'In the first weekend, I was anxious and I am still anxious, ' he said during Sky's Premier League coverage on Sunday. A real threat and on the counter-attack.
"You can see how comfortable he is with the ball at his feet and his delivery and passing so I was pleased".
Lampard added: "It is hard with the expectations at the start of the season was belief in the younger players because I felt they deserved a chance but there's always a question mark that you don't know until you see them there".
"But he has been training at a level and coming on at a level where he deserves his minutes today".
Images of USA operation against Baghdadi released
The new spokesman also sent a warning to the USA saying ISIS is still expanding worldwide, and said the group will seek revenge. Addressing the United States , the group reportedly said, "Do you not see how you have become the laughingstock of the nations".