The Suns also signed guard Ronnie Price for the rest of the season. In his third tenure with the team, Price, 33, has made two appearances since signing the first of two 10-day contracts Jan. 27.
On Thursday at the trade deadline, Phoenix got Sullinger and a pair of second-round picks from Toronto for forward P.J. Tucker, and acquired Scott, the rights to guard Cenk Akyol and cash considerations from Atlanta for a second-round pick.
The Suns face the Chicago Bulls on Friday night.