His salary right now is around $8.5m annually. If NYC took him on loan, they'd need to pay the full amount because MLS requires teams to do this to avoid getting around the salary cap that is in place. NYC could do this if they had a Designated Player spot open, but they don't at the moment. There are a few other issues though related to the fact their transfer window is closed and as someone else mentioned, their season ends fairly soon (about 8 games left then the playoffs which NYC are currently slated to qualify for).