O’Neill wants to add some firepower to his attack during the January transfer window, and the former Everton star, currently on the books of the New York Red Bulls, would provide at least a temporary solution.
The 33-year-old Australia international Cahill scored 68 goals in 278 appearances during his eight seasons at Everton before moving to the United States last summer.
He enjoyed some success against Sunderland during his time in England, finding the net seven times in 14 appearances against them for the Toffees and also denying them an FA Cup Final appearance in 2004 with a semi-final winner for Millwall.
O’Neill’s men have scored 21 goals in 20 league games to date this season with eight of them coming from summer signing Steven Fletcher and they are currently in 13th position five points clear of the drop zone.