Sharp, 20, signed for The Irons from Sheffield United last year and has taken League 1 by storm this season - leading the charts with 15 goals in 21 appearances.
A deal of about £1.5m is expected to be completed during the January transfer window.
Meanwhile, Sunderland have also been linked with another loan move for current Newcastle loanee, Giuseppe Rossi. The Man Utd & USA striker was the subject of rumours during the summer when a loan deal to Wearside was expected to be completed.
Also, Falkirk loanee, Anthony Stokes, looks set to stay at the SPL outfit until the end of the season after Arsene Wenger ruled out the sale of the striker. A great deal of Championship clubs, including Sunderland, were thought to be interested in the Irishman who has netted 13 times for Falkirk this season.