Per the Post:
A veteran of 51 NFL games and a return specialist as well, Blaylock, 27,worked out this weekend without a contract, but reached a verbal agreement with the team last night, according to his agent Michael Huyghue. Terms of the deal were not available.
More likely, the team sees a lot of value in a two-back system and recognizes that injuries happen, as they did last year. Saunders knows Blaylock and has used him productively in this offensive scheme as recently as 2004. He probably will not supplant either Betts or Portis, though he could become the complementary guy in front of Cartwright should either CP or Ladell go down with injury. Redskins now have seven RBs (as well as fullbacks Nehemiah Broughton and Mike Sellers) so this cannot be good news for Kerry Carter, Terry Caulley, and Marcus Mason. All presumably compete with Blaylock for finite roster spots in the backfield.