Signings like Foster, DJ, Foote, Burress etc. are typical Steeler signings going into the draft. They will not eliminate the desire for a BPA player at the same position, but also makes sure that those players are not a necessity.
If Patterson, Allen, Hopkins, Eifert, Cooper etc. are there and are BPA on the Steelers board, then they will not hesitate because they already signed someone.
This is exactly right. The Steelers always fill their spots with their own players or FA vets before the draft. They'll go with the BAP in the draft.