The former Michigan State Spartan was waived by the Pittsburgh Steelers last week.
The move comes following one of the worst performances by the Cardinals in team history, as Arizona suffered a 58-0 loss to the Seattle Seahawks. In that game, quarterbacks John Skelton and Ryan Lindley were a combined 19-of-39 for 133 yards, zero touchdowns and four interceptions.
Kevin Kolb, who regained his starting role after being beat out by Skelton in training camp, has missed the last seven games due to a rib injury. Since then, Arizona signal-callers have combined for just two touchdown passes and 14 interceptions.
Hoyer was waived by the Pittsburgh Steelers last week. In four seasons, he has appeared in 13 NFL games, only one of which has come in the last two seasons. In that span, he completed 27-of-43 passes for 286 yards, one touchdown and one interception.