According to Sky sources, Palace have agreed a fee with West Ham for Sakho understood to be between £10m and £12m.
Diafra Sakho could be staying in London for the time being - but almost certainly not with West Ham.
Smolov currently plays for Russian Premier League team Krasnodar and has scored 10 league goals in 13 appearances so far this season. And Hammers boss David Moyes is also thought to be keen on adding the Russian to his squad.
The attacker is expected to be one of the stars of next year's World Cup, and if he does have a huge impact for Russia, then his value would surely rise.
Their results have improved since Roy Hodgson took charge but form of star striker Christian Benteke, who has just one league goal, suggests the Eagles would benefit from another attacking threat.
Moyes has plenty of other forward options including Andy Carroll, Javier Hernandez and Andre Ayew, and the Scot should easily be able to cope without Sakho, especially considering the peripheral role he has played recently.
However, Sam Allardyce is ready to part ways with the striker after Everton completed the £27 million deal for Turkish striker Cenk Tosun.
"We are doing it as best we can and as professionally as we can. We don't want to bring players in for the sake of bringing them in".
The Hammers squad is incredibly imbalanced, and the addition of a central midfielder and centre-back will be Moyes' priority this month.