Manchester United stretched their flawless run under caretaker manager Ole Gunnar Solskjaer to seven wins from as many games in all competitions with a 2-1 home defeat of Brighton & Hove Albion in the Premier League on Saturday (Jan 19).
"You can't always play fantasy football".
"You can argue for many strikers but I'm glad he's in my team", Solskjaer said.
The club have won seven straight games under Solskjaer, who is the first United manager to win his first six league games in charge.
When you come here you know you've got to stay in the game, and we've paid the price for a slow start and poor goals conceded.
The Red Devils took the lead in the 27th minute when Paul Pogba scored his penalty, and Rashford netted a fine solo goal in the 42nd minute to put the home side in control. It is great working with him.
"He is so calm and assured when he is finishing".
'That was the first thing I said to him when I met him. At the start of the second half we could have finished the game with great chances. "At times we did and it's a great three points".
They face Arsenal in the FA Cup fourth round on Friday (19:55 GMT), live on BBC One, before returning to league action against Burnley on 29 January.
Solskjaer, who is Manchester United's record goalscorer as a substitute, added that Lukaku is now in a similar position to he was during his time at Old Trafford, where he often sat behind Andy Cole, Dwight Yorke and Teddy Sheringham in the pecking order.
"The gaffer [Ferguson] used to challenge us at times with 'Why can't you win 10 games on the bounce?'" Solskjaer said. "It's a challenge for us to get to where we as a club should be".
'As long as you take one game at a time and prepare well we should go into any game as winnable one.
"What I like the most is to get into their heads and find out what they are thinking".
"At the moment I don't think we'll be bringing anybody in, you can never say no in case something happens between now and the window, but with regards to what I think we need at the moment, no I don't think that will be the case". He has played all the games in the last few weeks.