However, the article seems to be speculating more than anything else.
From Yahoo! Sports:
Patten turns 32 in August, but he'll make an attractive and cheap option for receiver-needy teams like the Kansas City Chiefs, Chicago Bears and San Francisco 49ers. And though he flamed out in Washington, that's more of an indication of a poor fit and an even poorer signing
While a wide receiver may be of interest to the 49ers, head coach Mike Nolan has already confirmed that the team is very interested to see which defensive backs are cut.