Davis was released from the Dallas Cowboys in August – along with several other highly-paid veterans – as the Cowboys needed to get under the salary cap. Shortly after, Davis had a tryout with the Lions but was not signed.
He had a second tryout during the team's bye week and must have shown a marked improvement as the team didn't pass on the opportunity to add the former second-overall draft choice to their roster.
Davis is a three time Pro Bowler, being elected to the Pro Bowl for three consecutive years from 2007-2009.
The 33-year-old has proven to be an effective run blocker and figures to push Stephen Peterman at the right guard position.
The addition of Smith enables the Lions to add depth to a running back position that has been depleted through injury.
Also, Jerome Harrison was lost to an non-football medical issue.
Smith is a former third-round draft pick of the Lions -– 64th overall in 2008 –- and is already familiar with the coaching staff and the playbook.
During his rookie season, the former Central Florida product showed promise, tallying 1,262 yards from scrimmage and eight touchdowns. He missed significant time over the next two seasons due to knee and thumb injuries. He was not tendered an offer as a restricted free agent at the end of last season and became an unrestricted free agent but was not signed to any team.
In order to make room for Davis and Smith the team released running back Eldra Buckley and cornerback Anthony Madison.