Shawn Petty lined up, ready for the snap in a shotgun formation just like he had hundreds of times before. Petty dropped back, just like he always had, eluded a defender and cocked his left arm back, floating a perfectly placed pass to the right side of the end zone for a touchdown.

For one play, at least, there was nothing — other than the No. 31 on the back of his jersey and his 6-foot-1-inch, 230-pound frame — to indicate that he was anything other than a Division-I-caliber starting quarterback.

“Once he got settled in, we could see what we could do with him,” Maryland head coach Randy Edsall said during the postgame press conference following the Terrapins 33-13 loss to Georgia Tech on Saturday. “He showed his poise.”

But one play doesn’t tell the whole story.

For all the good that Petty displayed — a pair of touchdowns and a strong second half — there was still plenty of bad. An interception, a measly 24 yards on 17 carries and a first half that saw one complete pass.

Overall a 9-of-18, 115-yard performance is a bad day for any quarterback. But Petty isn’t any quarterback. In fact, he’s not a quarterback at all.

Petty arrived in College Park, Md., as a lightly recruited linebacker from nearby Eleanor Roosevelt High School. Petty made his name as an all-state linebacker, but he also starred as a quarterback, guiding the Raiders to a 10-1 season.

“I always thought that I could play at the D-I level,” Petty said during the postgame press conference. “Now I have my chance and I have to go prove it.”

He finally got that chance when an unfortunate situation turned tragically comic for the Terps. In the preseason, projected starting quarterback C.J. Brown tore his ACL, sidelining him for the entire year, an unfortunate blow for Maryland. Even a season-ending injury to new starter Perry Hills could just be labeled unlucky.

Just days after getting the news that Hills had torn his ACL and would miss the remainder of the season, the Terrapins were shocked to hear his backup Devin Burns would also miss the remainder of the season due to a left foot injury. UM was left with one scholarship quarterback, true freshman Caleb Rowe, and Petty as his backup.

That lasted one week. After just one game, the Terps received word that Rowe had torn his ACL, too.

Petty would have to make his collegiate debut at quarterback against the Yellow Jackets.

“I was just ready to play,” Petty said. “We play next man up so I had to be prepared.”

When Brown was expected to start the season for Maryland, the read option was supposed to be a major part of that offense. Even when he went down, Edsall was insistent on making it work with Hills and Burns despite the mixed results. When Rowe took over, the read option vanished.

But with Petty now at the helm, it’s returned.

Under head coach Tom Green at Eleanor Roosevelt, the read option was a staple. Much of Petty’s success was based around taking advantage of his size and speed in the read option, then following that up with the pass. Though he ran for fewer than two yards per carry in his debut, the read option has still made the transition a bit smoother.

“I am really comfortable with it because it’s a lot of stuff that I did in high school,” Petty said. “Some things came quicker than other things.”

Stefon Diggs also makes things easier for quarterbacks. The freshman wide receiver is the rare playmaker who can take a screen pass on one side of the field, make multiple defenders miss, then reverse the field for a 10-plus-yard gain.

Despite receiving passes from five different quarterbacks this season, Diggs has hauled in 43 passes for 721 yards and six touchdowns, including two on Saturday from the natural linebacker.

“He makes it a lot easier,” Petty said. “You give him the ball and he makes you look good. He’s a big playmaker so you want the ball in his hands a lot.”

He helped out on that touchdown to the right corner of the end zone that came on the final play on Saturday. Diggs had to reach up over the defender to grab the touchdown, but Petty’s throw was where nobody but the wide receiver could have reached it.

After completing just one pass for 1 yard in the first half, it was a brilliant finale that encapsulated just how much the linebacker had grown into a quarterback over the course of 60 minutes.

Now he’ll show just how much more he’ll transform for the Terrapins’ matchup with No. 10 Clemson on Saturday.

“That was a good way to end the game,” Diggs said after the game. “We ended strong and on a good note. We’ll be back next week.”