Please explain what you mean by "severely restricted". TIA

The rule will restrict the final eight teams in the playoffs from signing free agents. The final four teams shall not be permitted to negotiate and sign any unrestricted free agent to a player contract except for players who acquired their status by being cut or were on the final four team when their contract expired. Playoff teams five thru eight get a break to sign one player with a salary of $4,925,000 or more and any number of players with a first-year salary of no more than $3,275,000 and an annual increase of no more than 30 percent in the following years.
There is a mechanism to permit the final eight teams to sign an unrestricted free agent for each one of their own unrestricted free agents who sign with another club as long as they don't spend more than what their own lost player received from his new club.

5. The Final Eight Rule

The Saints, Colts, Vikings and Jets were the final four teams standing in 2009. They really can't sign any big free agents unless they lose a player and he signs for big money. For example, if Taylor signed with a team other than Minnesota for $6 million a year, the Vikings could then sign an unrestricted free agent for up to $6 million a year. Players like L.T. and Westbrook, who were released, do not factor into this rule and could be aggressively pursued by the final four. The next four teams left standing -- San Diego, Baltimore, Arizona and Dallas -- can each sign one big free agent for $5.8 million, but have restrictions after that. Don't expect much action from the final eight teams standing in last year's postseason.