The Irishman previously spent nine years with the Iron - winning three promotions along the way - and joins from Oldham.
His arrival is timely as Christian Ribeiro is doubtful due to a groin injury.
Right-back Ribeiro, forced out of last week's draw at Northampton, faces a late fitness test and if he fails to make it Eddie Nolan is expected to drop back into defence from midfield.
Skipper Michael Collins (knee) is still struggling, so boss Brian Laws could keep Matt Sparrow in a more central midfield role and recall Terry Hawkridge to the starting line-up on the wing.
Striker Chris Iwelumo made his first start for the club last week and is likely to retain his place up front alongside Sam Winnall, while fellow strikers Deon Burton and Jimmy Spencer are also in contention.