The Jazz announced Exum's injury was in his left shoulder and that he would not return against the Suns.
Per Spencer Checketts of 1280 The Zone, Exum ran right to Utah's locker room after crashing to the floor during the game.
Injuries remain a problem for Exum, who missed all of 2015-16 with a torn ACL and dealt with tendinitis among other issues in 2016-17.
When on the court, the 22-year-old has struggled to live up to expectations that come from being the No. 5 pick in the 2014 draft.
Exum averaged just 4.8 points and 2.4 assists per game during his rookie year despite starting 41 contests and wasn't much better in his third season with 6.2 points and 1.7 assists a night.
While his poor shooting and decision-making remain an issue, he continues to show flashes of solid play when he gets extended minutes.
"The reality is, Dante is getting better," head coach Quin Snyder said, per Tony Jones of the Salt Lake Tribune.
Unfortunately, the latest injury only provides more doubts about his ability to consistently contribute at a high level. The 6'6" guard still has great size and explosiveness, but that hasn't translated to production in the NBA.
The Jazz will have to rely more on the combination of starter Ricky Rubio and Raul Neto at point until Exum is ready to return.
The team opens the 2017-18 regular season at home Oct. 18 against the Denver Nuggets.