Bell suffered the injury in the first quarter of the Demons' NAB Challenge match against Adelaide in Elizabeth.
However, the prognosis for Liam Jurrah - who also dislocated his shoulder against the Crows - is not yet known.
Jurrah had scans on Sunday but a statement released by Melbourne said further clarification was needed on his injury.
The statement read: "The club will seek further consultation over the coming days to determine the final extent of any damage."
Midfielder Nathan Jones also left the ground at one stage with what appeared to be an injured ankle, but football manager Chris Connolly said there was nothing more than general soreness among the rest of the group.
Bell, 24, was sidelined until round 10 last season with a broken thumb and dislocated his shoulder in round 15 and didn’t return. The hard-working defender has played 66 games.
Forward Jurrah, the first player picked at the 2009 NAB AFL Pre-Season Draft, played nine games in his debut season and booted 20 goals.
