Sakho's return is a particularly relief for manager Sam Allardyce after the Frenchman made a blistering start to his Premier League career by scoring in six-successive matches, before a shoulder injury sustained on international duty last month curtailed his progress.
The 24-year-old, who has not featured since their clash with Aston Villa in early November, has come through a full week of training and is in contention to face Garry Monk's men.
Song has also been in impressive form since moving to Upton Park on a season-long loan deal from Barcelona in the last transfer window.
He has missed the last three matches with a knock, but is set to provide more options in midfield for Allardyce this weekend.
"Sakho and Song have been training all this week so the opportunity for them to join the squad this weekend is good," he said.
"Having Enner [Valencia] and Sakho back, Andy [Carroll] getting fitness, [Mauro] Zarate and Carlton Cole, our striking options are great."
Allardyce feels the key to beating Swansea at Upton Park lies in stopping in-form striker Wilfried Bony.
The Ivory Coast international has six Premier League goals to his name this season and Allardyce wants a collective team effort to stem his threat.
"I think it's difficult to stop Bony," he added. "Hopefully on the day we'll keep him quiet but he is in terrific form at the moment.
"It's about the team as a whole stopping the supply."
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