Denver announced the deal on Friday, while Walker's agent Drew Rosenhaus had leaked the agreement Thursday on the agent's Twitter.com site.

Walker signed with the Houston Texans as a free agent in 2007 and played four games, rushing for 264 yards on 58 carries and catching 13 passes for 81 yards.

He dressed for five games with the Texans last season but did not play before joining St. Louis' practice squad for a week on Nov. 4. He rejoined Houston's practice squad on Nov. 25, finishing the season with the Texans.

In addition to drafting Georgia running back Knowshon Moreno in the first round of this year's draft, this offseason the Broncos have now signed four free-agent running backs — adding Walker to a group including Correll Buckhalter, J.J. Arrington and Lamont Jordan.