In years past the NFL was very locked down for Free Agency. The longer time goes on though, the more lenient the league becomes.
In former years the league allowed players and teams to do everything but actually agree to any offers or come to agreements. It does make sense to a degree, but I can't imagine how the execution works.
"So, say we made a contract of 4 yr. 40 million. Do you know a receiver that would like that?"
"Yeah, I know a receiver who would take that deal."
Doesn't work, but the NFL didn't want teams locking down players before the day and time of free agency actually occured.
ProFootballTalk acquired a March 2 memo that all teams receive. Quotes from the memo:
"During the two-day negotiating period, all clubs may negotiate all aspects of an NFL Player Contract with the certified agent of any prospective UFA. However, a new club may not execute an NFL Player Contract with a prospective UFA until 4:00 p.m., New York time, on March 9, when the player's 2015 contract expires."
Verbal agreements folks, and this could be exciting. Agents that want to be known in the league with the phrase, "word is bond" has enough reputation to get deals done. But the word doesn't have to be, and can't guarantee anything. Even the memo brings light to the surface.
"the only valid, binding and enforceable employment agreement between an NFL player and an NFL club is an NFL Player Contract that has been fully executed by the parties in compliance with all applicable League rules and the CBA."
Breaking this part down, it means without a true contract signed in the Free Agency period that player is not accountable for anything, and neither is the club offering a contract.
"are non-binding and are unenforceable by the player or the club"
Same as before, nobody gets anything that was spoken for unless it's a true NFL Player Contract signed in the actual Free Agency period.
The reason they attempt such a stand has to do with the League's Anti-Tampering Policy, a very good and respectable law. If this policy were to be violated an investigation will be required. The league also will take all relevant documents from the franchise under suspicion. This includes emails, any phone communications, and any documents reviewed travel arrangements for the player.
No player nor franchise would enjoy the league taking a peak at the emails or phone call & texts they are doing.
Two examples of this behavior being the Ndamukong Suh problem, when they reportedly finalized a deal before FA began.
Another being the weird actions the NFL were about to take against Harbaugh and Haloti Ngata, when talking about if Haloti would end his career back as a Raven. It was a very interesting debacle, but just like the Suh reports, no action was taken.
I do believe that deals will be struck before official FA starts, but this could become something quite interesting. A player or team going back on a deal is always just a bit exciting, unless it happens to Baltimore of course. We all remember the Terrell Owens fiasco.