That means that unless the Texans agree to new contracts with these 15 players before free agency begins on March 10th, they'll hit the open market. Note that agents can officially begin negotiations for impending free agents on March 7th, so that may well be the actual deadline for teams to come to terms with players that will fetch interest from around the league. Kareem Jackson, Ryan Mallett, and Derek Newton would seem likely to be in that class, and others (Brooks Reed? Kendrick Lewis?) could find themselves in demand by multiple suitors as well.
Strap in. This has the potential to be quite a ride.