"It might take us some time, but if we all stick to the game plan, work collectively as a team, and we've got a good manager who knows the club and who shares the same ambition, who knows what we can achieve?"
The coach said the club had "got a good deal" from Inter Milan for Lukaku and wished him the best, while tipping 17-year-old Mason Greenwood to step up to replace the Belgian global.
Manchester United coach Ole Gunnar Solskjaer told fans on the eve of the new Premier League season that although there is no quick fix to the problems which dogged the club last season he is feeling "confident" about the forthcoming campaign. I am paid to manage - and this is not just about me getting results now to help my reputation or whatever.
"I think Ole has looked at that and probably Lukaku has looked at that. Solskjaer always took his chances and was clinical in front of goal and if he can pass that down to Rashford, then he'll score 20-30 goals a season".More news: Watch Tenacious D And Jack White Meet Up For ‘Jack Gray’ Collaboration
"It's not just me".
"Hopefully you should see the signs of the team I would want to be in 12 months".
He added: "Let's make sure now that we are part of Manchester United that we surprise a few people".
Former Chelsea and Real Madrid manager Mourinho also admitted he did not believe United could win the title last season before he was sacked in December.More news: Chris Cuomo Confronts Guy Who Called Him Fredo
"We are speaking about United that finished sixth and Arsenal that finished fifth".
"It's also a little bit hard for me, in spite of obviously some good players, I don't see also Arsenal to resist to a title race like last season, last season was phenomenal".
"With the same amount of rest this year we've been able to schedule training, it's been a lot more individualised and I feel a lot better for it".
Speaking to Sky Sports ahead of Manchester United's clash against Chelsea on Sunday, Mourinho highlighted the pool of talent available to Pep Guardiola.More news: Alisson out 'the next few weeks' with calf injury
Spain, France and Germany all close their transfer windows on August 31, while Italy's slams shut on the 18th.