SANTA CLARA, Calif. -- Marcus Lattimore knows Friday is coming."It's rough," Lattimore said Wednesday as he prepared for his final practice week of the season.The former South Carolina star running back, who the San Francisco 49ers drafted in the fourth round of the April draft, is in the third week of a three-week window where the NFL allows players coming off injuries to participate in practice.As has been the plan, the 49ers will shut down Lattimore for the rest of the season.