With free agency about to begin, Cardinals General Manager Steve Keim (left), director of football operations Mike Disner and the rest of the front office will be busy.

Free agents cannot sign with other teams until Thursday – 2 p.m. Arizona time is the beginning of the new league year, when players' contracts officially expire – but free agency essentially starts two days sooner than that.

Beginning Tuesday at 10 a.m. (Arizona time), the NFL will open its "legal tampering" period, when teams can officially speak to scheduled free agents and the market for 2017 can start to sort itself out.

For the Cardinals, it'll bring some final clarity to some of their own free-agents-to-be that the team was hoping to bring back. At

the top of the list have been defensive lineman Calais Campbell and safety Tony Jefferson, both of whom are expected to find significant offers elsewhere.

Various reports – fueled by speculation while agents and teams worked the Scouting combine in Indianapolis over the last week – have Jefferson potentially getting as much as a $10-million average on a new deal. Campbell is expected to get even more money than that. Those numbers figure to price the Cardinals out of a reunion with either.

The Cardinals still have more than a dozen of their own free agents that could still potentially return, and there remains a chance some could sign in the next couple of days, before the market opens.

Who the Cards will chase from other teams will be in part determined by who they can bring back. Last year, GM Steve Keim made the point that the Cardinals know where they want to land on the contracts of their own players and "draw your line in the sand," understanding upon which point the team is willing to move on.

With outside targets, needs and price drive the conversation but like potential draftees, the person becomes as important as his playing.

"The hard part about free agency is, you can find some good players out there, but sometimes the things you know internally about the players and the reasons they hit free agency, whether it is a guy who struggles mentally or a guy who is not the greatest worker, now all of a sudden you inherit those things you didn't know about a player," Keim said. "So you have to do your homework, not only in terms of tape, but you have to use your sources outside the building – with other teams, guys who have worked with them, to try and make sure you are getting the right person and the right fit for your locker room."

Keim has said chemistry and leadership are an area he wants to focus on within 2017 roster building after missing some of that during a disappointing 2016 season.

During the tampering period, teams cannot talk to a player directly, only his agent. Travel plans for a visit cannot be made. And while negotations on a contract can begin, a contract agreement cannot be reached.