Siakam's return would be a boost to a Raptors lineup that also had to play Wednesday's 112-110 overtime win over the Charlotte Hornets without Fred VanVleet, Marc Gasol, Dewan Hernandez and Norman Powell due to injuries.
Raptors coach Nick Nurse told reporters that Siakam, Gasol and Powell all took part in Friday's practice on a limited basis.
Siakam has not played since Dec. 18, when he suffered a groin injury during an awkward landing. He told reporters Friday that he had hoped to play two weeks ago but had to trust the guidance of the team's medical staff.
He is averaging a team-leading 25.1 points and 8.0 rebounds in 27 games this season. He is among the Eastern Conference leaders in All-Star voting.
Powell is expected to play Sunday against the Spurs, Nurse said, adding that Siakam and Gasol could return in the near future.