Nnamdi Asomugha was widely considered to be among the best cornerbacks in the NFL before a disappointing two-year detour through Philadelphia.Might the 31-year-old veteran find a career rebirth in San Francisco?Asomugha's scheduled visit to the 49ers sounds exciting, but it's tough to know which direction San Francisco is headed with some of its free-agent visitors. The team could simply be weighing its options and waiting out the market. Charles Woodson came and went from team headquarters Wednesday, for example.