If they draft a corner to eventually step into the role then will not need to lock up Samuel long term and will just do what it takes to get him into camp. But that would also mean that a high enough offer would make trading Samuel now and getting value for him also a good bet.
Doing that before the draft would get you the best value for this season, if you intend to deal him this year. If you deal him after the draft, you are taking a shot on where the other team might end up. If you intend to keep Samuel, you better get the deal, in principle, done before the draft so you know what your real needs are. If you wait until after, then you are relying only on what is left in the free agent market and what you have to trade for and lose value next year.