DeAndre' Bembry (hamstring), Gary Trent Jr. (ankle) and Jalen Harris (hip) are currently listed as doubtful for Friday's game.
The Raptors are coming off back-to-back games against the Atlanta Hawks and San Antonio Spurs on Tuesday and Wednesday. Lowry sat against the Hawks, but played against the Spurs. Siakam and Anunoby played over 34 minutes in both games.
Bembry will miss his third straight game due to hamstring tightness and rookie Jalen Harris last played on March 14.
Fred VanVleet will likely return to the lineup on Friday after serving a one-game suspension for leaving the bench during a scuffle with the Los Angeles Lakers last week. He previously missed six games before serving the suspension due to a hip injury.