Petty — a former linebacker — hadn't thrown a pass in a game since high school.
But the freshman and his coaches planned to immediately show the Yellow Jackets on Saturday that he could throw often and accurately enough to keep the defense guessing about Maryland's play selection. The Terps wanted Georgia Tech to respect the pass so that it would be unable to stack the box with extra defenders against the run.
"Coming into the game, they thought I couldn't throw — knew I couldn't throw, I guess," Petty said after Georgia Tech defeated the Terps, 33-13. "We just wanted to come out and show we could get the ball off — we could throw the ball and we could run the ball."
But Petty's first play did not make the statement that Maryland intended.
Taking the snap at Maryland's 23-yard line, Petty faded back and looked for a receiver but was sacked for a 4-yard loss.
The sack was not the fault of the offensive line, Maryland coach Randy Edsall said Sunday after watching the game video.
"It was Shawn," Edsall said. "He could have gone to any of the three guys that we had out there."
Petty, who is expected to remain the starter, was elevated to first team after injuries to three quarterbacks in two weeks. In all, Maryland has lost four quarterbacks to season-ending injuries since training camp began, leaving the Terps in what the program calls "uncharted territory."
The 230-pound Petty, who began the season as a scout team linebacker, was quickly taught offensive terminology and began throwing the ball in practice a few weeks ago. "I had to get my arm back," Petty said.
Petty was initially Maryland's backup quarterback and became the starter after Caleb Rowe tore his anterior cruciate ligament against Boston College on Oct. 27.
Petty's teammates said they were as curious as the fans to see if a linebacker could smoothly make the transition to quarterback and leader.
Before Saturday's game began, Petty's teammates patted his helmet as they walked past him on the sideline to encourage him.
"Everyone didn't think he was a really good quarterback and he came out and showed them that he could do it," tailback Wes Brown said after the Georgia Tech game.
But Petty had a rough first half. His only completion was a 1-yarder to Stefon Diggs, and the Terps trailed 20-0 at halftime.
In the second half, Petty threw two touchdown passes to Diggs — 16 and 23 yards.
He said he felt at ease running the ball. He gained 56 yards on 17 carries but was credited with only 24 rushing yards because of losses from sacks. He often ran the ball on options during his playing days at Eleanor Roosevelt High School in Greenbelt.
"I'm really comfortable with the zone reads and everything," Petty said. "It's a lot of stuff that I did in high school. A lot of it came easier and quicker than the other things."
Petty completed 9 of 18 passes for 115 yards. He was intercepted on a line-drive pass intended for Diggs in the fourth quarter.
"I tried to tell him that you need to see that [defender] and put the ball up in the air over top of him and let Stefon go up and get it," Edsall said.
"I think he got better as the second half went on," Edsall said. "I told the team I am very proud of him for how he handled the situation."