He caught the eye with some stunning goals despite the Millers' relegation to League Two, and was linked with a move to Wolves.
The Scot has one year left on his contract, and according to reports he is in talks with the Iron over a move.
Woods began his career at Leeds United, but made just one substitute appearance for the Yorkshire side before mocing to Sunderland.
He made eight Premiership appearances for the Black Cats, but moved to Rotherham last summer after being released.
If confirmed, Woods would become United's second signing of the summer after the arrival of winger Kevan Hurst from Sheffield United.