PITTSBURGH -- Fast doesn't adequately describe Devin Bush, according to one teammate.

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"He's quicker than snot," linebacker T.J. Watt said. "He's been flying around and making a lot of good plays."

The early returns on the Pittsburgh Steelers' first top-10 pick in nearly two decades have been largely positive.

The 2019 draft featured two inside linebackers expected to contribute right away. One was Devin White, who has made an immediate impact with the Tampa Bay Bucs. The other, Bush, the former Michigan inside linebacker acquired via a draft-day trade with the Denver Broncos, has put his 4.43 speed on full display in the three weeks of OTAs.

To be sure, the Steelers won't know exactly what they have until they put on the pads for training camp. But a No. 10 overall pick is expected to have a presence from day one, and Bush has.

"He's not the biggest guy, but he definitely walks with a presence, walks with a purpose," Watt said of the 5-foot-11, 234-pound Bush. "He's taken on a good role in knowing all the plays and being able to call some plays for us."

Bush has made clear since his introductory news conference that he isn't looking to replace Ryan Shazier, whose speed made him a two-time Pro Bowler on the inside before a severe spinal injury stalled his career. Bush understands the expectations. The team's last top-10 pick was Plaxico Burress, No. 8 overall in 2000.

Bush simply wants to maximize his capacity and play Steelers football. That process is going strong, and his athletic traits are obvious.

But the Steelers still need one thing from him: a stronger voice in the huddle and at the line of scrimmage. Defensive end Cam Heyward joked last month that Bush needs more boom in his voice if he's going to call plays for this veteran group.

Steelers first-round pick Devin Bush works through some agility drills during OTAs. Keith Srakocic/Associated Press

"He showed really quickly he’s going to be able to fit in well with the defense with that group of guys," tight end Vance McDonald said. "When you look at him, you don’t expect him to be as quick or as agile as he is. There's a couple of things he needs to work on: being more vocal, because of the role Coach Tomlin wants him to fit into quickly, and the expectation of him doing that. But that’s still such a young thing. You never want to overstep, especially when the pressure is on. I think that will come, especially in Latrobe as he gets the pads on."

That's when McDonald and others expect Bush to really shine with physicality. For now, he's doing what he was taught to do more than a decade ago: Cover receivers in space.

Bush has received first-team reps but is sharing time with free-agent acquisition Mark Barron, who figures to play in base or nickel packages. Bush has lined up with tight ends and running backs and looks comfortable in either setting, particularly at the goal line.

"He’s been flying around, especially seeing him in the seven shots period. He’s high intensity, doing a good job covering people," backup quarterback Mason Rudolph said. "You can see his athleticism, and he’s learning quick."