Even signing a contract worth millions may not have been the highlight of Kobbie Mainoo ’s week. The poster boy for the Michael Carrick revolution at Manchester United capped the transformation in both his fortunes and theirs with a goal whose significance was as much emotional as financial. United clinched their return to the European elite. “Qualifying for the Champions League felt off in the distance at one point,” said Carrick. He has made it a reality. And though a draw was all his side required, the winner Mainoo drilled in completed a double over Liverpool, ensured a comeback from Arne Slot ’s side that was simultaneously inspired and illogical was in vain, and gave United further reasons to appoint Carrick . “I love doing what I am doing,” he said. “It feels pretty natural.” Kobbie Mainoo stroked home the winner for Manchester United (Reuters) He looks a natural fit. He has been on quite a run. He has beaten Manchester City, Arsenal, Chelsea and now Liverpool.…