New chief executive Richard Arnold told fans last week that the club are struggling to find the funds to develop Old Trafford.
According to the Mirror, the Red Devils are contemplating taking out a mortgage to fund renovations to their stadium and the Carrington training ground.
A naming rights deal similar to the one agreed between Spotify and Barcelona could also be considered for Old Trafford, but the United hierarchy would be concerned about the subsequent backlash from supporters.
With Man United's debt currently in the region of £500m, taking out a mortgage would take that figure closer to the £1bn mark, especially as work to the Sir Bobby Charlton Stand would cost around £300m.
Despite the risk of their debt heading towards £1bn, Arnold has previously indicated that funds are available for new United boss Erik ten Hag to use this summer.