The San Francisco 49ers' interest in free-agent receivers Julian Edelman, who is visiting the team today fresh off a 105-catch season in New England, and Hakeem Nicks, says this: the team is clearly interested in using more three-receiver sets.After all, it's not like Anquan Boldin (who just signed a two-year, $12 million extension) and Michael Crabtree (who is in his prime) are going to see decreased roles in the offense.The NFL is a league of three-receiver sets, although the 49ers did not subscribe to that theory.