The former Everton hitman joined up with Jose Mourinho's team earlier this week in LA following his £75million move.
Lukaku, 24, was on holiday with Pogba prior to his switch to Old Trafford.
And United's record signing helped to see the Belgium international snub a return to Chelsea to sign for the Red Devils.
Lukaku has been brought in to significantly bolster Mourinho's frontline.
Despite the boss admitting in his first pre-season press conference today there is a chance Zlatan Ibrahimovic could yet sign a new deal, Lukaku will lead the line immediately.
Jesse Lingard, Paul Pogba and Eric Bailly have all helped Romelu Lukaku settle at Manchester United
Romelu and Paul are very close
After a week in training, Lingard outlined his new team-mate has gelled well with United's players.
Lingard also has a good relationship with Paul Pogba, and Lukaku will seemingly be joining their friendship group in Manchester.
On the new signings Lukaku and Victor Lindelof, Lingard said: "Yeah they’ve settled very well, it’s an easy squad to integrate with, Romelu and Paul are very close.
“Romelu has settled in well, we know what he do with the goals he scores. If he can bring that here it would be a big help.
Romelu Lukaku in Manchester United's first training session Mon, July 10, 2017
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Romelu Lukaku got stuck into Man Utd's first training session of pre-season
“Romelu is very strong and physical and I think he will cause defenders problems this season, we’ve seen it in training.”
Lukaku and Lindelof could make their debuts for Manchester United when they take on LA Galaxy in their first friendly of the summer on Sunday (3am).
Lingard, meanwhile, is looking to establish his own place in Mourinho's team ahead of the new campaign.
He added: "I think everyone plays their part in the team, you have to try and be involved in as many goals as possible. I’m working on it.
“I’m 24 now and I’ve been around a very long time, there is a lot of responsibility playing for best club in the world.”