Don't be surprised if the Niners focus on fortifying their defensive line early in the upcoming draft. In a perfect world, we hear, the team wouldn't mind rotating fresh bodies up front more often. For one thing, there are age and injury factors that come into play. DRT Justin Smith is 32 years old, and NT Isaac Sopoaga turns 31 before the start of next season. DLT Ray McDonald is only 27, but his knees have given him problems on and off for a while now. The Niners have no problem with current backups Ricky Jean Francois, Demarcus Dobbs and Ian Williams (word is they particularly like Jean Francois), but we hear more manpower would be welcomed. Breathers were few and far between this season for Smith and McDonald, who performed above and beyond the call of duty and displayed tremendous stamina before wear and tear appeared to take their toll in the last two regular-season games.