Bell, Mims, and Cashman will be eligible to return on Oct. 11 when the Jets host the Arizona Cardinals at MetLife Stadium.
Without Bell, the Jets will turn to Frank Gore and Josh Adams to pick up the slack in the running game. The team also signed RB Kalen Ballage to the active roster on Tuesday.
Meanwhile, New York is hopeful that rookie RB La'Michal Perine (who is dealing with an ankle injury) won't be out much longer, per SNY's Ralph Vacchiano.
As far as what Gang Green can do at wide receiver without Mims, they'll have to rely on an already-thin corps that is led by Jamison Crowder, Breshad Perriman, and Chris Hogan.
Bell's injury came in the third quarter while he was running a route downfield. He seemed to try and speed up to catch the throw from QB Sam Darnold, but he came off the turf holding his left leg a bit.
Bell didn't have any ailments during training camp that required him to miss time, but there was one instance during a team scrimmage were he was sidelined because of hamstring tightness. He called it a miscommunication and said it wasn't an issue to worry about.
Bell was having a tough time with the Bills' defense before getting hurt, being held to 14 yards rushing on six carries. He had two catches for 32 yards.