Wayne Rooney rejoined his old club as Romelu Lukaku travelled in the opposite direction to his new one. Manchester United’s executive vice-chairman, Ed Woodward, saluted the Everton-bound Rooney as “our greatest-ever goalscorer” while Lukaku revealed he would never have been able to turn down an offer from Old Trafford, describing his new employers as “the biggest club in the world”.

In his first interview since his move from Everton was confirmed, for a fee of £75m rising to £90m with add-ons, the Belgium striker neglected to express any sort of gratitude for his time on Merseyside and suggested slightly provocatively that he was joining the side with the best fans in the country.

“This is an opportunity I’ve always wanted since I was a child,” Lukaku told ESPN. “When Manchester United came calling I didn’t have to think twice. I’m really delighted to be part of their history. Who would say no to the biggest club in the world? This is the perfect opportunity. Best stadium in England, the best fans. My mind was already set, I gave my word and I don’t look back.”

Lukaku is already in the United States, where he will now have to return for a court appearance in October after receiving a police misdemeanour citation for making excessive noise while on holiday in Los Angeles, and will join the rest of the United squad who have flown out for a four-match pre-season tour.

The player completed a medical over the weekend and is expected to be unveiled in a United shirt in Los Angeles in the next couple of days. Lukaku is thrilled to be joining up with his close friend Paul Pogba and, like the Frenchman with whom he shares an agent in Mino Raiola, appears to have been convinced that United are on an upward curve despite missing out on a top-four finish last season.

“I think United at the minute want to be the dominant team, that dominant force,” he said . “If you look at their history, it says enough. To become part of a club like them is something that I really wanted. I’m thankful for the opportunity they have given me; I always said I wanted to play for a team that’s challenging for every trophy there is.”

Chelsea were willing to match the package that took Lukaku to Old Trafford and were initially confident they could revive a deal for a long-term transfer target even after United’s coup had been announced, but the London club must have finally given up hope once the player began posting pictures of his medical on social media and enthusiastically signing the shirt of a young United fan.

Chelsea are now expected to switch their attention to Real Madrid’s Álvaro Morata, a striker said to be stunned at how quickly his projected move to Manchester United broke down, and may even consider a move for his team-mate James Rodríguez, similarly disillusioned by the lack of first-team opportunities at the Bernabéu. Antonio Conte did manage to land one of his summer targets on Sunday, with Roma’s Germany defender Antonio Rüdiger in London for a medical ahead of a £34m move.

Ronald Koeman has been considerably more successful in the transfer window so far and was proud to announce Rooney’s capture on a two-year deal for an undisclosed fee. United’s record goalscorer and erstwhile captain was finding it difficult to get into the team at Old Trafford or make any significant impact as a substitute, though the Everton manager remains confident he still has what it takes. “Wayne has shown me the ambition that we need and that winning mentality – he knows how to win titles and I’m really happy he’s decided to come home,” Koeman said. “He loves Everton and he was desperate to come back. He is still only 31 and I don’t have any doubts about his qualities. It’s fantastic he’s here.”

Rooney made his Everton debut in 2002 aged 16 and, before leaving for United in 2004, scored 17 goals for the club in 77 appearances. In his 13 years at Old Trafford he won every available club honour, culminating with a Europa League medal in his final appearance as a substitute in Stockholm in May. In addition to the Champions League, Europa League, five Premier League titles, an FA Cup and three League Cups, Rooney broke Sir Bobby Charlton’s scoring records both for United and for England. His combined goal tally for club and country stands at 323 and he is England’s most capped outfield player.

Paying tribute to his departing striker before leaving for America, José Mourinho said Rooney’s records would remain in the history books for many years to come. “It is no secret I have long been an admirer of Wayne. He has been a model professional throughout his time at the club,” the United manager said. “It is never easy to see a great player playing less football than he would like and, when he asked to go back to Everton, I could not stand in his way. His experience, focus and determination will be missed and I wish him well for the future.”

Woodward added: “Wayne goes having created some of the most magical moments in some of the most successful years in the club’s history, he has been a fantastic servant to United. On behalf of the club and millions of fans around the world we wish him the very best for the next phase of his incredible career.”