Dwyer played for Cardinals coach Bruce Arians in Pittsburgh.
A former sixth-round draft pick, Dwyer rushed for 197 yards on 49 carries last season.
Two seasons ago, he started six games and rushed for 623 yards.
The Cardinals signed center-guard Ted Larsen.
Larsen has started 31 of 60 career games. He has previously played for the Tampa Bay Buccaneers.
The Cardinals re-signed linebacker Marcus Benard. He played in a dozen games last season for the Cardinals last year.
The Cardinals also retained linebacker Matt Shaughnessy on a two-year deal.
Follow me on Twitter: @RavensInsider
Aaron Wilson covers the Ravens for The Baltimore Sun