(Santa Clara, CA)  --  The San Francisco 49ers are losing three more starters to the coronavirus.  NFL Network reports the Niners will place wide receivers Brandon Aiyuk and Deebo Samuel and offensive tackle Trent Williams on the COVID-19 list.  The trio are considered "high-risk close contacts" of wide out Kendrick Bourne, who has tested positive for the virus.  The Niners shut down their team facility on Wednesday following Bourne's positive test but are still expected to host Green Bay tonight.