Golden State Warriors hero Green is one of millions of American sports fans increasingly keen on soccer and was pictured on Friday wearing a Manchester United shirt alongside Paul Pogba and Romelu Lukaku in a snap posted by the club's official Instagram account.
Pogba and Lukaku are both big basketball fans and so were all smiles wearing blue Warriors jerseys as Green posed in United's famous red strip.
But fast forward to Monday and Green, an NBA champion with Golden State in two of the last three NBA seasons, was seen with different colours and a different football superstar.
Barcelona, who are also on tour in America and will meet United in an International Champions Cup friendly later this month, presented Green with a shirt bearing Neymar's name, while Neymar held up a Warriors jersey with Green's #23 for another all smiles Instagram snap.
With split loyalties, who will Green be rooting for when United and Barcelona meet at the FedEXField in Landover on 26th July?