The Arizona Cardinals do not have very much salary cap space right now. After adding Evan Mathis and Chris Johnson, they are now iat a point in which they might have to shed salary to add any other players.
According to the latest NFLPA report, Arizona has just under $4 million left in salary cap room. The exact number is $3,974,926, and that is calculating only the top 51 contracts of the team. They have 77 under contract right now.
Salary shedding moves will have to come along soon if they want to add anyone else of any significance.