Rangers are reportedly hoping to land a triple swoop on Newcastle.
Rangers are reeling after Sunday's 2-0 defeat to Old Firm rivals Celtic, but are looking to give fans a boost with some signings.
The influence of shareholder Mike Ashley could come into play, with the Newcastle owner keen to lend Rangers some of the Magpies' youngsters.
Reports earlier in the day, as claimed by The Chronicle, suggested that former Coventry City midfielder Gael Bigirimana would move north of the border having struggled for first-team football this season, and he could be joined by two more familiar faces.
The Chronicle suggest that defender Mbabu and forward Vuckic could follow Bigirimana to Ibrox today, with Newcastle willing to let them leave to play regularly.
Mbabu, 19, is a Swiss youth international who predominantly plays at centre-back, but can also play on the right hand side of a back four.
Despite being highly rated, the former Servette man has yet to play in the Premier League for Newcastle, so earning some playing time may be beneficial to all parties.
Meanwhile, Slovenian forward Vuckic has played in a number of positions during his career, including out wide, up front or behind a striker, and failed to impress during recent loan spells with Cardiff City and Rotherham United.
The 22-year-old hasn't kicked on in recent years, and having seen Kenny Miller toil away up front on his own against Celtic on Sunday, Vuckic may be the man to provide some much needed support in the final third.