Later today, the New England Patriots will open their 2018 organized team activities. Over the next four weeks, the team will work on teaching and implementing early schematic concepts and taking the next step after the initial two phases of workouts. While not all players will be present at least early on, there will still be plenty of intriguing storylines to follow. Let's take a look at some of them.

When will Brady and Gronkowski show up...

While the Patriots' two biggest stars will not attend the early portions of OTAs, the duo will likely return to join its teammates no later than June 5: New England opens its mandatory minicamp that day and both Brady and Gronkowski are expected to be on the practice fields when that happens. The question is whether or not one or both return earlier – and in which capacity if that is the case.

...and how will their replacements look?

With Brady and Gronkowski missing at least today’s practice, the depth players behind them will get more reps. At quarterback, veteran Brian Hoyer and rookie Danny Etling benefit by the starter not being present as both will see more chances than usual when it comes to leading the offense through drills. At tight end, meanwhile, a variety of players – headed by Dwayne Allen and Jacob Hollister – will be the next men up.

Will there be early signs of second-year jumps?

From former draft choices Deatrich Wise Jr. and Derek Rivers to 2017 free agency additions Stephon Gilmore and Rex Burkhead, New England has plenty of players on its roster entering their second year in the system. Year two is typically when a player takes a significant step in his development and it will be interesting to see if there will be some early signs of that visible during OTAs – be it in terms of usage, build, or general demeanor.

How will the position battles develop?

Even though not all players currently under contract will be present for OTAs, there will still be plenty of competition over the next four weeks – most notably at the wide receiver and cornerback positions: Both spots have multiple players eying for a limited number of roster spots and while the battles will not be decided in mid-May, players can very well position themselves to make a run at one of the spots on the 53-man squad.

What will Bret Bielema's role be?

Former Arkansas head coach Bret Bielema first appeared with the Patriots during the scouting combine. Since then, he remained with the team and appears to be well on his way to join the staff. OTAs – the first opportunity for reporters to watch the team practice – might give more indication as to what the 48-year old's role in New England might ultimately look like.

How will Dont'a Hightower and other players coming off IR look?

In 2017, the Patriots saw plenty of core players wind up on season-ending injured reserve: Linebacker Dont'a Hightower, wide receiver Julian Edelman, and right offensive tackle Marcus Cannon are just three of the starters to end their campaigns on the sidelines. All three will be back this year and are expected to participate in OTA practices – just like depth players Nate Ebner, Malcolm Mitchell, and Derek Rivers.