The wide receivers with the two biggest names -- and two of the biggest bodies -- are poised to sign elsewhere when free agency begins on Wednesday.
Sammy Watkins, who last year played for the Los Angeles Rams, will join the Kansas City Chiefs on a three-year deal that offers as much as $48 million, according to the NFL Network.
Jaguars receiver Allen Robinson, meanwhile, is set to become a Chicago Bear. His deal also has been reported to be three years and $42 million.
Robinson and Watkins have had been linked to the 49ers because of San Francisco's abundant salary-cap space and the fact that Kyle Shanahan has lamented his lack of tall receivers.