Ladarius Green is the Steelers' $4.75-million mystery

Tight end Ladarius Green is eager to get to work with Ben Roethlisberger. It's unclear when that will happen. Charles LeClaire/USA Today Sports

Ladarius Green is around the team during practices, goes to lunch with the team and stands on the sideline for games. During the early portion of each practice session, Green usually runs under the watchful eye of a trainer, maybe adding a few light cuts or footwork drills.

But his career in Pittsburgh remains tethered to mystery.

There's still no clarity on Green's future with the Steelers other than coach Mike Tomlin reiterates he's on the physically unable to perform list because of offseason ankle surgery. Tomlin said he isn't addressing an NFL Network report that Green is suffering from recurring headaches.

The only certainty is Green received a $4.75-million signing bonus in March as the team's biggest free agent acquisition.

The Steelers didn't pay him that money -- a four-year deal worth up to $20 million -- because of his 1,087 career yards and seven touchdowns from four seasons in San Diego.

The money represents more than that:

-- The Steelers' strategy to go vertical at the tight end position after Heath Miller's retirement.

-- A potential answer to the loss of Martavis Bryant.

-- A team that doesn't throw out big money for free agents very often taking a chance on a playmaker.

All that doesn't matter if Green can't get game-ready by Week 1, and the clock is ticking.

Even if the Steelers anticipated a lengthy rehab from the ankle surgery, which required the insertion of two metal plates, no one expected such a fuzzy outlook this deep into August. In general terms, teams won't give hefty signing bonuses to players who openly struggle with post-concussion issues. I checked with people from two NFL teams about Green's free agency file, and all that was known was he had multiple concussions at San Diego but no red flags in this area.

So, now, with Le'Veon Bell's looming suspension and Green's issues, here's the Steelers' potential Week 1 list of starting playmakers: Antonio Brown, Markus Wheaton (Eli Rogers in the slot), DeAngelo Williams, Jesse James.

Ben Roethlisberger can make that work -- he and Brown always give their team a chance -- and Williams is more than capable, but this wasn't the opening day lineup everyone envisioned two months ago.

There's little doubt Brown will push for 200-plus targets this year. With all the change, he's safety valve one, two, three, four and five. From what I've gathered, the Steelers like James but need to find out if they love him. He'll need to become a stout inline blocker to earn that trust.

Also expect Bell, whether he plays 12 or 16 games, to be heavily involved in the passing game, particularly in the red zone. His pass-catching ability can help offset some of the losses.

Let's be careful in this space not to write Green off. He's got time, and he hasn't given his full story. He told reporters in March that his concussions in San Diego were misdiagnosed. NFL teams can designate one Injured Reserve player to return later in the year, so perhaps that's an option for Green if his recovery is slow.

But this pair doesn't have a chance yet, and both parties hope they at least get that.

In offseason workouts, Roethlisberger referred to Green as a Ferrari stuck in the impound lot. Big Ben throwing sky balls to a 6-foot-6 athletic freak up the seam would be imposing.