The fact of the matter is, the NFL is not like other sport at all. The nature of it doesn't lend itself to a trade deadline with multiple high-profile moves or veterans changing teams to win a championship.
The NFL season, though long on the calender, only has 16 games, so changing personnel is not in the best interest of any club.
Continuity wins championships.
Not only that, but teams spend the entire training camp and preseason finding out their strengths and weaknesses, so most have addressed those weaknesses before the season starts.
So while the NBA and MLB trade deadlines are highly televised and covered by major media outlets, the NFL deadline often comes and goes without anyone really noticing.
Most teams have put their eggs in their basket by now, and NFL front offices realize that the spring is when transactions are going to take place.
Sure you'll have many signings and releases during the season, but never any major trades. While I do believe they have looked into making a trade, I doubt the Giants make a move on either of these players.