Far from it, Lukaku has revealed he is looking forward to lining up alongside the Swede and has welcomed the competition his presence will bring to the front line.
The striker scored 28 goals in 46 total appearances for the Premier League side last season, and the 35-year-old will be a huge bonus for the Red Devils this season.
Lukaku has begun his United career in style by scoring three goals in his first three Premier League games for the club, and he carried his fine goalscoring form into the worldwide break.
"I said to Zlatan I hoped he would be back".
Former United striker Saha added: 'Lukaku is the player who can score 25 goals a season but he is also capable of scoring the very decisive ones.
"I think they look like [Premier League] favourites, but it is not a sprint, it is a marathon - you have a lot of competition, a lot of games", Saha told reporters.
Ex Arsenal midfielder Merson hailed Lukaku as the signing of the summer for his goals and his ability to get the best out of Manchester United's talented midfielder.
"I'm now working under the manager I wanted to work with for a long time".
"It gets tougher and tougher to win that Champions League". Ibrahimovic has been posting regular updates about his training and looks to be making quicker than expected progress, which led United to offer him another contract and re-sign him during the recently concluded summer transfer window.