Lukaku has been settling into life at Old Trafford after having signed for the Red Devils from Everton in the summer transfer window last year.
The 24-year-old has been in good form for the Red Devils since his move, scoring 14 goals and making seven assists in 29 Premier League games for Jose Mourinho’s men to help them up into second place in the table.
And Manchester City defender Otamendi has admitted that coming up against Lukaku is as hard as facing FC Barcelona attacker Luis Suarez.
Otamendi told Spanish newspaper Marca when asked which strikers have made him struggle: “There are many. Luis Suarez is a striker who is constantly moving, making diagonal runs, creating space, then you always have to be prepared to run.
“Then [Romelu] Lukaku is another very strong player, technically good, quick… It’s between those two.”
Meanwhile, Manchester United are set to return to Premier League action on Saturday when they host Swansea City at Old Trafford.
The Red Devils are currently in second place in the Premier League table as they look to try and secure qualification for next season’s Champions League under Mourinho.
Manchester United finished in sixth place in the top flight last term but they won both the Europa League and League Cup in Mourinho’s first campaign in charge at Old Trafford.
The Red Devils were knocked out of the Champions League at the last 16 stage by Sevilla last month.
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