PITTSBURGH — More than half an hour after practice ended at UPMC Rooney Sports Complex, the wheels of the JUGS machines kept spinning. Thunk. Thunk. Thunk. The machines spit out football after football after football in the direction of Roman Wilson.The 24-year-old receiver caught a bucket’s worth of balls reaching to his right. A bucket’s worth of balls reaching behind him. A bucket’s worth of balls on one knee. A bucket’s worth of balls on the other knee. A bucket’s worth of balls sitting down.Meanwhile, coach Mike McCarthy — standing just about 20 yards away — fielded a question about what Wilson will need to do to take the next step as he enters Year 3.“Just keep doing exactly what he’s doing,” McCarthy said, glancing over in the receiver’s direction. “He’s been here from Day 1. He was one of the first men to reach out and just clearly ask what the expectation was of him, how I viewed him, how I saw him fitting in, as far as X, F and Z.“He’s doing the work. He’s had a great offseason, so I just need him to keep showing up and keep working his tail off, because he’s got a skill set. There’s a lot there to work with.”As Wilson prepares to enter his third NFL season, he is one of the significant X-factors that has the potential to swing the wide receiver room and the offense as a whole in one direction or another. If he takes a substantial step forward, earns Aaron Rodgers’ trust and uses his versatility to contribute at all three receiver positions, the Steelers will have one of the most well-rounded and deep receiver rooms they’ve had in years.At the same time, even after adding Germie Bernard in the draft, the Steelers need Wilson to seize his opportunity. Last year, the third receiver on the depth chart was a rotational player in one of the least receiver-friendly offenses in the league. In a McCarthy offense that will utilize a ton of 11 personnel (one back, one tight end and three receivers), the Steelers will need three or more starting-caliber players at the position.