The Belgium global has enjoyed an impressive start to his United career since his reported £75million move from Everton, scoring three times in three Premier League appearances to help his side to nine points.
Clubs will still be able to sell to other leagues across Europe whose transfer windows remain open later into August and September.
It was in his single season with West Brom in 2012/13 that Lukaku first got off the mark in the Premier League, scoring 17 times for the Baggies that season. Perhaps that's why Diego Forlan - who scored in nearly every other game during his time in Argentina - found it so hard to get up and running after making the switch to Manchester United in January 2002.
"Hopefully there are still things for us to exploit".
Moyes was simply too incompetent to ever guide United forward, while Van Gaal could never really engender a style that his players or supporters ever truly believed in.
During his post-match interview, the Stoke City manager said: "I pushed him because he was in my technical area". That's why I say that winning the FA Cup has actually been my biggest achievement as a coach, because despite the noose around your neck, you have to keep those players motivated.
Van Gaal also suggested United's owners are more focused on commercial ambitions rather than sporting goals, in comments that may be viewed as a subtle dig at his former employers.
They could win their opening two Premier League home fixtures for just the second time. Martial had a down year last season following a storming first campaign in the red shirt, but as he begins to resurrect his game back to the level of two years ago, surely he will want the volume of starts to reflect such form.
Mourinho blamed the global break for a United showing that failed to match the high-octane performances that preceded it.
Romelu Lukaku has scored 16 goals in his last 18 league matches. He can count himself lucky that it did no lasting damage to his reputation, but it still has to be recorded as one of the worst goal droughts - from an otherwise incredible player - in Premier League history.