The Suns have not announced a timetable for Warren's return, and he is out indefinitely. He averaged 4.4 points and 2.4 rebounds while shooting 50 percent from the field during the preseason.
Warren, 21, was the No. 14 pick in the 2014 draft out of North Carolina State. He was named Atlantic Coast Conference player of the year last season after scoring 24.9 points per game on 52.5 percent shooting for the Wolfpack.
He is the third Phoenix player to injure a finger during the preseason. Second-year center Alex Len fractured a finger after getting it caught in an opponent's jersey, and free-agent acquisition Anthony Tolliver cut a finger on a jersey. Len and Tolliver have each already returned to the lineup.
Warren will compete with veterans P.J. Tucker, Marcus Morris and Gerald Green for playing time at small forward for the Suns.
Phoenix plays its final preseason game on Friday against the Utah Jazz before opening the regular season on Wednesday against the Lakers at home.
- Paul Palladino