DeAndre Hopkins
The first three wide receivers on this list are long-term options and probably will command massive contracts in free agency. However, the Bills may only go that route if this upcoming season players like Coleman or Shakir really struggle.
If Coleman and Shakir play well, the Bills may want to add a veteran who can compliment these wide receivers and be a leader for the position. In that scenario, then DeAndre Hopkins could be the best option in free agency next year.
Hopkins is set to play his second season in Tennessee after a decade of football split between the Houston Texans and Arizona Cardinals. Last offseason, the Cardinals released Hopkins and at the time the Bills seemed to be in the discussion to sign him as a free agent.
According to Sports Illustrated's Albert Breer, the Bills went through the process but ultimately decided Hopkins might upset the offense and particularly their number-one wide receiver at the time. However, with Diggs no longer in Buffalo that might not be an issue, and if Hopkins puts together a similar season to what he did this past year with the Titans, he could be a good fit in this offense.