The former Tottenham striker, who moved to MLS club Toronto FC in February, could be set for a swift return to the Premier League before the transfer window closes.
Harry Redknapp is keen to be reunited with the striker, who he managed at Tottenham, Portsmouth and West Ham. But a return to Upton Park, where Defoe emerged from the youth system and made his name, is also on the cards.
Newcastle and Sunderland are also understood to be interested in a move for the former Spurs man, who moved to MLS at the end of February 2014.
Toronto general manager Tim Bezbatchenko on Sunday confirmed the club has received offers for the striker.
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"As far as I'm concerned, Jermain Defoe is with TFC," Bezbatchenko said. "It's important for Jermain to be here, because he is a great player. But if things change then we'll adjust. We receive offers all the time, especially for a player like Jermain.
"We have received an offer and we have discussed it internally. I think that when you score as many goals as he has and you have the reputation and background that he has it's not uncommon to receive these offers.
"We've received, actually, multiple offers before over the course of this year. So I want to confirm that we're in talks, but we have a relationship with Jermain too. We're speaking with him and no decisions have been made. We'll discuss it over the next 24 hours."