A planned joint venture between the Premier League club and the Las Vegas Sands Corp for a large entertainment complex featuring a casino sited next to the Old Trafford stadium could fall foul of NFL rules.
The NFL has however ruled that Glazer's control of United does not infringe the League's rules on cross-ownership, reports the BBC.
The League added it had no problem with the debt Glazer has incurred after seizing control of United.
The news came during a meeting of NFL team owners, the first such meeting since Glazer took a controlling share in the club - a move that has cost £790million, leading to fears he may use the Buccaneers as collateral for his debts.
The NFL is known to be wary about gambling links and has asked Glazer for more information about the casino plans.
"The only potential issue concerns that reported Man United joint venture with the Las Vegas casino, what that means, and does it have any implications regarding our policies," an NFL spokesman said.
