CLEVELAND -- First it was Kyle Bradish. Then came Adley Rutschman, Terrin Vavra, DL Hall and Kyle Stowers.

And now: Gunnar Henderson.

The Orioles promoted Henderson, their No. 1 prospect and MLB’s No. 2 -- their second time doing exactly that this season (after Rutschman) -- ahead of Wednesday’s tilt against the Guardians in Cleveland, adding one of the most highly touted youngsters in the game to the roster amid the team’s postseason push.

• Waiting for a burger, Gunnar first got a callup

Excitement for Henderson has been building for months, his hype coming in tandem with his success. And now he’s here.

Why is he such a big deal?

Henderson’s arrival caps off a meteoric rise, as he started the year as baseball’s No. 41 prospect with only five games above Single-A, and he represents another top prospect joining Baltimore’s ranks. Tagged a “flagship” of the Orioles’ revamped player-development system, Henderson was a highly skilled but raw high schooler when the organization took him in the second round of the 2019 Draft and is now a refined five-tool threat for years to come.

Put it all another way: Henderson compiled a .944 OPS across 112 games for Double-A Bowie and Triple-A Norfolk. Along the way, he never faced a pitcher younger than him. Just before his callup, he rattled off three hits and stole a pair of bags for Norfolk on Tuesday night.

How will the Orioles use him?

In the weeks before calling up Henderson, the Orioles tasked him with learning both second and first base, positions he had not previously started at professionally. That was done with flexibility in mind, though it remains to be seen how creative they get with him in the bigs. Realistically, he’s expected to get the lion’s share of reps at third base, possibly creating some sort of platoon with Ramón Urías, or instead moving Urías to second. A natural shortstop, Henderson projects to be a plus defender at third, and the emergence of Jorge Mateo has created a bit of a blockade there -- at least this season.

What can we expect from Henderson?

In the Orioles’ mind, a superstar talent who very well could be the most exciting player to come from the rebuild. Though strikeouts crept up in Norfolk, Henderson has shown a keen maturity at the plate with power alongside it. On the field, his athleticism is enough for the club to believe they may be promoting one of their best defensive infield prospects since Manny Machado.

What number will he wear?

Henderson will sport No. 2, a switch from his No. 13 with Norfolk. Freddy Galvis is the most recent Oriole to wear the number, though its most popular association in Baltimore (outside of Derek Jeter, for unfortunate reasons) is the team’s last shortstop stalwart, J.J. Hardy.

How old is Henderson?

Just 21. Henderson was the youngest player at the Triple-A level when he was promoted in June (he was 20 at the time), and yes, he’s yet to face a pitcher younger than him this season. He’s the youngest Oriole to make his debut since Machado did at 20 years old in 2012.

Who are Henderson’s player comparisons?

Corey Seager -- Henderson is another tall shortstop who hits for power from the left side. (Seager also happens to be one of Henderson’s favorite players.) Henderson may very well stick at third base in the long term, due in part to Jackson Holliday’s placement in the system and because he might be better profiled there, with above-average defense at the position.

Where is he from?

When the Orioles drafted Henderson in 2019, they lured him away from what appeared to be a solid commitment to Auburn, signing him to an overslot $2.3 million bonus. The Selma, Ala., native was bred on a backyard baseball diamond built by his father. An All-State basketball player as well, Henderson ultimately stuck with baseball -- and it appears to have paid off handsomely.