Ex-NBA Player Sean Rooks -- Dead At 46

Ex-NBA player and current Philadelphia 76ers assistant coach Sean Rooks has died ... the team announced in a statement.

The 46-year-old -- who starred at the University of Arizona -- played 12 seasons in the NBA ... including stints with the Lakers, Mavericks and Timberwolves.

Our sources tell us ... it appears Rooks may have had a heart attack during dinner.

Rooks' mother issued a statement saying, "It is with deep sadness and overwhelming grief that we mourn the sudden loss of my son, Sean."

"Our family asks that our privacy be respected as we grieve during this incredibly difficult time."