The Red Devils signed Lukaku in a £75m deal from Premier League rivals Everton in the summer transfer window to make him the second-most expensive signing of all time at Old Trafford.
Lukaku hit the ground running with 10 goals in nine games in all competitions to quash any concerns about his ability to play for a top team.
However, the Belgian forward went on a six-game goal drought before he scored in Manchester United’s 4-1 victory over Newcastle United.
Ibrahimovic made his long-awaited return from a serious knee problem in Manchester United’s win against Newcastle to provide Lukaku with competition for starting spot.
The former Sweden international netted 28 times in all competitions last season to help Manchester United to win the League Cup and the Europa League.
However, Ibrahimovic will presumably have to compete with Lukaku for a starting spot given Jose Mourinho has stuck with a 4-3-3 formation this term.
Asked whether Lukaku and Ibrahimovic could play as a twosome up front, former Liverpool defender Carragher told Sky Sports:
“I don’t think they can play together as a front two.”
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