Senegalese striker Sakho, who has been a revelation at Upton Park this season, has been missing since sustaining a shoulder problem while away on international duty last month.
But he now looks set to return to help the Hammers continue their charge towards a European berth.
Song, who is also been in impressive form since his arrival the club, is in line to feature at Upton Park too having recovered from the knee injury which has sidelined him for the past month.
“Sakho and Alex Song have been training all this week so the opportunity for them to join the squad is good,” Hammers boss Sam Allardyce revealed at his pre-match press conference.
Mark Noble, however, is struggling to be fit for the clash with the Welsh club.
The homegrown midfielder missed the midweek win at West Brom with a calf injury and is rated 50/50 to be ready for Sunday’s game.