Len initially fractured the finger during the Suns first summer league game in July, and missed the entire slate of games.
The 7-foot-1 center was the No. 5 draft pick in 2013 out of Maryland. He had ankle surgery that summer and was hampered by foot problems last season.
"As long as it’s not my feet or nothing like that, I’m fine,” Len said. “It’s just a pinky, so I don’t get discouraged."
As a rookie, Len appeared in 42 games, averaging 2.0 points and 2.4 rebounds in 8.6 minutes per game.
The Suns begin preseason play on Wednesday against Rio de Janeiro Flemengo. Their first regular season game is Oct. 29 at home against the Lakers.
- Molly Geary