Roy, who joined Minnesota after a one-year retirement forced by his ailing knees, hadn't played in a game since Nov. 9.
The 28-year-old, three-time all-star has had seven procedures done on his knees.
Roy averaged 19.0 points, 4.3 rebounds and 4.7 assists in five seasons with Portland, but 5.8 points and 4.6 assists in five games for the Timberwolves.
Minnesota also is without all-star forward Kevin Love (broken hand), starting point guard Ricky Rubio (ACL surgery) and swingman Chase Budinger (left knee surgery).
Center Nikola Pekovic (ankle) and guard J.J. Barea (foot) also have missed time.