A left-winger is one of the United manager’s top priorities in the transfer market this summer and Hall is high on his wish-list.
The 18-year-old from Aylesbury was a big hit on loan with the U’s last season, scoring six goals in 12 starts during two separate spells.
It coincided with the team’s most productive spell in front of goal and despite his brief stay ended up as the side’s joint third highest scorer.
Wilder, who released winger Oli Johnson this month to free up space in the squad, is keen on bringing Hall back on a season-long loan.
The U’s chief thinks the chances of a deal would be improved if the Hammers went up to the Premier League, where the teenager is unlikely to feature regularly.
He said: “I think if West Ham do go up I think it would be a good option for us and for Robbie because he’s only a kid.
“That’s why we kept that open, it was a difficult one with Oli, but it’s no good us signing him and then we’ve got nowhere to go.
“We’ve got a fantastic relationship with West Ham and you never know regarding Robbie coming in for next season on a long-term loan.
“There have been talks at boardroom level about that, I don’t really want to be talking to (West Ham manager) Sam Allardyce at this stage when he’s got a Championship final to prepare for.”
United are hoping improvements in injury prevention will make them less reliant on loan players next season than they were in this campaign, when it was seen as a factor in the team’s late season slump.
But Wilder is not totally put off and still sees it as a valuable talent pool, with arrangements benefitting all parties.
He said: “Whether it’s Robbie or someone of a similar ilk who’s lurking in someone’s reserve side.
“We sourced Robbie and Lee Holmes (from Southampton) like that, we’ll keep our options open and see what becomes available.
“Deals are there to be done in terms of payment – not only is Robbie getting good experience, West Ham are benefitting from it as well and we’re not having to pay a decent-sized wage.”