.Source: 49ers have Aiyuk field structure along with Browns, Patriots NBC Athletics Bay AreaBrandon Aiyuk profession requirement: 49ers WR very likely to be handled than receive extension from San Francisco, every file CBS SportsReport: 49ers possess framework in place for Brandon Aiyuk trade with 2 teams San Francisco ChronicleReport: 49ers have exercised frameworks of Brandon Aiyuk patronizes Browns, Patriots 49ers Webzone49ers expert provides most recent improve on Aiyuk as field reports swirl Yahoo Sports.