The clock is ticking.

Before Tuesday at 4:00 p.m. ET, all rosters must reduce from 90 to 53.

There were no half steps this year. It's one deadline. One move. Thirty-seven roster spots created, in one fell swoop.

Some teams already have begun to make moves, which makes sense. The preseason is over, with the exception of tonight's Texans-Saints game. Most teams can easily shed 30 players, right now. For many teams, some of the final seven spots will be created by keeping one or more players on the reserve/PUP or reserve/NFI list. Other spots can be created after the reduction to 53, by moving players to short-term injured reserve.

After the rosters move to 53, there will be a scramble to claim players on waivers and/or to sign vested veterans who have become free agents. That will shake up the bottom of some rosters, resulting in players who made the 53-man roster not making it for more than a day beyond the deadline. Then, those players can spark another round of churning at the bottom of rosters, something that will happen all season long.

Practice squads will be formed, giving many players who didn't make the active roster a chance to stick around, and for many to get called up on game day.

There's also one more dynamic to watch. More trades can happen between now and Tuesday. In lieu of cutting a player, a team could try to trade him. The Saints, for example, could dangle to the Broncos a player or two who was acquired and developed by Sean Payton — and whom Payton might want to bring to Denver.

Regardless of how it plays out, there will be plenty of activity over the next few days. As always, we'll be tracking all of it here.