Tottenham and Portsmouth have agreed a fee for Defoe, leaving the player to decide whether he wants to move to Fratton Park.
He has also struggled for regular opportunities under head coach Juande Ramos, with the Spaniard preferring Robbie Keane and Dimitar Berbatov in attack for important matches.
Ramos and Defoe fell out after a training ground incident at the start of the month but have since patched up their relationship, and the striker has talked about signing a new deal.
However, his lack of action has seen him linked with other Barclays Premier League clubs.
Pompey boss Harry Redknapp, who worked with Defoe at West Ham, was monitoring the striker's situation in the summer but no deal was agreed.