Samuel hasn't shown much. Injuries are part of the game and I dont think we should bank on the hope that he will be injury free and contribute in any big fashion. Also, too early to tell if Coleman can show progress. Coleman is seemingly putting in the offseason work, which is good, but whether it translates to on-field success remains to be seen.
In short, we have two proven WRs and two who are questionable in their ability to contribute significantly. We need at least one, maybe two more additions.