The Cleveland Plain Dealer said some of the injuries could take months or longer to heal.
The PD said Brown suffered what's believed to be a ruptured biceps tendon in his right arm and will most likely need surgery.
Jackson suffered what could be a serious injury to his right knee, leaving the stadium on crutches. Jackson was supposed to replace William Green for the rest of the season.
Beasley was carried to an ambulance on a stretcher with what may be a broken right ankle. He was replacing Paul Zukauskas.
The Browns lost the Monday night game 26-20.