In a statement, the Suns said the shooting guard will be reevaluated in three weeks.
Beal missed the team's first seven games with his lower back strain, then returned Nov. 8 for the first of three straight games before missing Wednesday's win over Minnesota.
A three-time All-Star, Beal is averaging 17.3 points, 5.3 rebounds and 3.7 assists in three games, all starts.
Acquired from the Washington Wizards in an offseason trade, Beal was expected to form a high-powered big three in Phoenix, but injuries have prevented that from happening.
Devin Booker has also played in just three of the Suns' 11 games because of ankle and calf injuries, but has not appeared in a regular-season game with Beal. Kevin Durant has been the team's lone superstar constant, as the 35-year-old has not yet missed a game.
Phoenix (5-6) plays the first of two consecutive games at Utah (4-7) on Friday night.