.Source: 49ers possess Aiyuk field structure with Browns, Patriots NBC Athletics Bay AreaBrandon Aiyuk field requirement: 49ers WR most likely to be handled than receive extension coming from San Francisco, per file CBS SportsReport: 49ers possess framework in place for Brandon Aiyuk patronize two crews San Francisco ChronicleReport: 49ers have worked out platforms of Brandon Aiyuk trades with Browns, Patriots 49ers Webzone49ers insider offers most recent improve on Aiyuk as business rumors swirl Yahoo Sports.