Lukaku joined the Red Devils from Everton on July 10 for an initial £75million, a fee that could rise to £90m with add-ons, and the striker has had five days training with his team-mates in Los Angeles on their pre-season tour.
The Belgium international has the difficult task of replacing Zlatan Ibrahimovic, who left Old Trafford at the end of last season after scoring 17 goals from 28 Premier League appearances.
United's new arrival, who is only 24, had an equally impressive scoring record in his time at Goodison Park, bagging 68 league goals from 141 top-flight matches, and he will be hopeful of continuing that fine form at the Theatre of Dreams.
Lukaku has already been making an impression on his new team-mates and Lingard, who signed a new four-year contract in April, believes the striker will make a huge impact when the new season starts.
"He's a very strong lad, very physical presence, and he's going to cause defenders problems this season," he said. "We've seen it in training, we've already witnessed what he can do in training and if he can bring that it will be huge."
United have also signed defender Victor Lindelof this summer whilst recent reports are suggesting a move for Chelsea's defensive midfielder Nemanja Matic and Inter Milan's Ivan Perisic are edging closer.
Manager Jose Mourinho appears to be building a squad capable of challenging for silverware on the domestic and international stage and, if the rumoured deals go through, punters may decide to use their free bet on United adding a 21st English title to their collection.