23-year-old midfielder Bas Sibum was reportedly scouted by Forest in last week's game against ADO Den Haag, while defender Peter Niemeyer came to the Reds attention in the same game.
Sibum joined Twente in July 2003 and has played 17 games in the Dutch top-flight this season. Niemeyer has 25 games under his belt.
Moves for either player would require a transfer fee as they are firmly under contract.