Currently, the Seahawks have just one other quarterback on the roster besides Russell Wilson. Paxton Lynch is the only other member of the quarterback room. Lynch, the former first-round pick, is a fine risk to take, but should not be the only option for the backup QB spot.
Of course, there is no way he will be. The Seahawks will need to add at least another arm or two for rookie mini-camp and an additional arm or two for training camp. So Seattle will add a QB or two in the coming months.