Bell, who is third on the No. 24 Bulldogs with 12.7 points per game through 13 games, suffered the injury in Saturday's win over the Santa Clara Broncos.
The 6'1 junior is shooting a career-high 50.9 percent, and his performance has been particularly strong from the perimeter. He's shot 47.6 percent from beyond the arc so far this season, second on the team to Kevin Pangos' 47.7 percent from deep.
Gerard Coleman, who transferred to Gonzaga from the Providence Friars, will likely step into the primary off-guard spot in Bell's absence. Through 13 games, Coleman averaged 7.9 points in 12.5 minutes per game off the bench, though he's not a 3-point shooter. Louisville Cardinals transfer Angel Nunez, who played in his first game Saturday after becoming eligible after Gonzaga's first academic semester concluded, will also help fill the void.