With the roster currently at 18 players, Sportsnet's Michael Grange says Ishmail Wainrrigh, Sam Dekker and Isaac Bonga will likely battle for the last spot. The decision is not likely to come today.
NBA teams can carry 15 players plus an additional two two-way players.
The six-foot-eight Gillespie played 20 games with the Raptors last year, averaging 5.6 points and 4.9 rebounds.
The six-foot-nine Perry averaged 3.0 points and 2.8 rebounds in 26 games with the Brooklyn Nets last season.
The Raptors open their season Oct. 20 against Washington.