PITTSBURGH -- Steelers coach Mike Tomlin let Antonio Brown know who was ready for him.

"Two-five," Tomlin said to Brown as the star receiver stretched before Friday's rain-soaked training camp opener.

And Brown replied, "Hopefully."

Sure, No. 25, Artie Burns, lost a few downfield plays to Brown, as is customary for anyone guarding him. But early indications are Burns, last year's first-round pick, is better equipped to pester Brown in Year 2.

Burns had to refine his game as a rookie, but he's never been afraid to cover Brown. He does it every practice. And he's fearless about it. The Steelers love that about him. The next step is anticipating with footwork, technique and discipline, areas in which Burns is improving.

Take Friday's training camp opener. Brown got past Burns twice early in the session, including on a deep ball down the sideline. But Burns battled back with a pass breakup, and he also was in on a physical play involving safety Sean Davis over the middle that knocked Brown down and knocked the ball loose.

Tomlin won't give Burns props for simply battling against Brown. That's what first-round picks should do, Tomlin says. But Burns is looking to turn that fearlessness into turnovers soon enough.

Some other observations from the first day of camp, which did not include pads.

* Running back James Conner got plenty of touches in his first NFL practice and ran with a finisher's mentality. Running backs are difficult to evaluate without pads, but Conner looked eager to produce. On one carry, Conner kept running to the end zone well after the play was over. "All the emotional parts, the 'wow, I'm in the NFL,' that's behind me now," Conner said.

* One intriguing connection to watch is Ben Roethlisberger and Justin Hunter, the lanky free agent signee who hasn't maximized his potential in four NFL seasons, all without a top-shelf quarterback.

That changes now. Roethlisberger and Hunter connected on a slick back-shoulder play in individual work, with Roethlisberger explaining the play to Hunter in detail beforehand.

In "seven shots" -- offense vs. defense at the goal line -- Hunter got loose on a crossing route for an easy score.

If Martavis Bryant takes a while to return, perhaps Hunter can fill the role as a long and fast deep threat.

* On his first official training camp snap as a full-time starter, linebacker Vince Williams broke up a pass intended for Jesse James at the goal line.

* This is hardly a revelation, but Roethlisberger's arm looks very healthy. In warmups, he fired an over-the-middle shot to James that nearly whistled.