The Reds will play two games in Portugual and coach Steve Wigley is backing 31-year-old Leigertwood to make an impact despite a knee injury forcing him out of the weekend friendly against Ilkeston.
"He has done well in training and the fact is that we have not got a midfield player of his type, in a powerful figure with real physical presence," said Wigley.
Forest take on Porto B at the Estadio de Pedroso on Wednesday at 6pm in the first of their two fixtures.
***Update*** The signing of Roger Riera from Barcelona has been confirmed.