Ready for football? Offseason activities will have to suffice

We won't yet hear the crack of pads — or even see a set of seven-on-sevens — but for a football-starved nation, here are some glorious words: NFL players are back to work.

Players are allowed at their team headquarters today to begin the first phase of the offseason program, which, for now, consists of little more than weightlifting and conditioning under the supervision of strength coaches.

But these organized team activities (OTAs) will soon lead to limited on-field work and eventually minicamps. The seven teams with new head coaches were allowed to begin their offseason programs April 7.

Here's what you need to know about the offseason program:

Is this mandatory?

Unlike training camp later this year, most of the offseason program is voluntary. But many players have bonuses tied to their attendance, and coaches and executives are paying attention to who shows up and who doesn't. Players will make $175 a day for participating in the program.

What can players do?

In addition to strength and conditioning, quarterbacks and wide receivers can play catch, but that's as close to football as you're going to get in the first phase that lasts three weeks.

When does on-field work start?

Coaches are allowed back on the field with their players in Phase Two. There will be individual position drills and team work for offense and defense, but players on opposite sides of the ball can't face each other. This phase lasts for three weeks, after which Phase Three begins. This is finally when it will feel more like football. Teams will hold minicamps (and the teams with new head coaches can hold two of the three-day camps). Players will wear helmets and go through offense-vs.-defense drills, though there will be no live contact and players won't be in full pads.

Why are these practices important?

Coaches have spent much of the offseason retooling their play books, and these practices are the first chance to begin testing new plays. Teams with veteran coaches and established quarterbacks will often try to install much of the playbook in the spring to get a head start on training camp. Rosters will have also changed plenty over the last few months, and this is the first chance for players to begin getting used to playing with each other.

What are the risks?

Though there is no contact allowed during OTAs, there are risks. Last year, San Francisco 49ers receiver Michael Crabtree tore an Achilles tendon and San Diego Chargers outside linebacker Melvin Ingram suffered a torn anterior cruciate ligament in May.

What about the rookies?

The NFL draft has been pushed back two weeks and will be in May, but that doesn't mean rookies will miss much time with their new teams. All OTAs start after the draft. Each team is also allowed to hold a rookies-only minicamp the weekend after the draft.

Follow national NFL reporter Lindsay Jones on Twitter at @bylindsayhjones.