Portsmouth are still trying to push through a deal to sign Kanu and avoid starting the season with just one fit striker.
Despite new owner Alexandre Gaydamak's millions, manager Harry Redknapp has not yet been able to bring to Fratton Park the top-quality frontman he craves.
He has secured his defence with the signings of goalkeeper David James from Manchester City for £1.2million, centre-half Sol Campbell on a free transfer from Arsenal and right-back Glen Johnson on loan from Chelsea.
But with last January's club record signing Benjani Mwaruwari struggling to overcome a thigh injury and Lomana LuaLua out for at least two more weeks through a damaged ankle, Redknapp has failed to land a string of top targets.
Now he could be left with only Todorov against Blackburn on Saturday and admitted: 'We have made offers, but we have not been able to get the people we wanted.'
He told the Portsmouth News: 'At the moment I have only got `Toddy' - and I cannot play him up front on his own.
'We are struggling for strikers and I desperately need at least two more.'
Kanu, the 6ft 5ins former Arsenal forward who was freed by relegated West Brom at the end of last season, still looks Redknapp's best bet, although both Valencia and Hamburg are said to be interested in signing him.
Redknapp said: 'We are talking to Kanu and hope to get something done soon. He is a clever footballer, a good player.'
Todorov made only six starts, scoring four goals, last season having spent the best part of two years recovering from a cruciate knee ligament injury which required two operations.
Benjani arrived from French club Auxerre for a £4.1million and scored only one goal in 16 games. Now St Etienne are reportedly interested in him but Redknapp said: 'There is no chance of `Benji' going anywhere.'
The Zimbabwe striker needed a knee operation in the summer, however, and has since been troubled by a thigh strain.
Redknapp has had bids turned down for Jermain Defoe (Tottenham), Stilian Petrov (Celtic) and Obafemi Martins (Inter Milan), and made made no progress with a plan to take former Arsenal and Real Madrid striker Nicolas Anelka on loan from Turkey's Fenerbahce.
He still has Benfica's Portugal midfielder Manuel Fernandez and Peruvian left-back Juan Vargas training with Pompey, but neither player has yet signed a contract.
And with senior goalkeepers Dean Kiely (thigh) and Jamie Ashdown (broken thumb) out for the start of the season, Redknapp will have to put untried Nick Jordan, 17, on the bench on Saturday unless he can snap up a short-term loan signing.