Trent Richardson is tentatively scheduled to have arthroscopic surgery on his left knee Thursday to remove a "hang nail particle" of loose cartilage, according to sources. Richardson is expected to return to the field for the Browns before the regular season opener. The small particle, which has caused swelling, will be "cleaned up" by Dr. James Andrews. Richardson could manage the knee without surgery, but the decision was made to be proactive about the injury, according to a Cleveland source.