Shawn Petty quarterbacks Eleanor Roosevelt against Wise last season. He’ll get an unexpected opportunity to play the position again on Saturday. (James A. Parcell/FOR WASHINGTON POST)

When the final whistle sounded and a gloomy Eleanor Roosevelt football team trudged off its home field last November, an undefeated record spoiled by a 13-8 loss to C.H. Flowers in the 4A South region semifinals, Shawn Petty had his mind made up. A two-way threat for Coach Tom Green and the Raiders, Petty was committed as a linebacker to the University of Maryland. He had no choice. Zero college offers to play quarterback came his way.

So Petty quit throwing footballs and began pumping iron, bulking up for his next stop along the Terrapins’ defensive front seven. He would redshirt his freshman season, learning blitzes and protections from the veterans scattered throughout a talented unit, then compete for playing time next year. He would stand on the sideline in sweatpants at home games and cheer on his teammates, toiling on the scout team and waiting for an opportunity.

That was the plan. Then everything went haywire in the alternate universe of the Maryland football team, where the unpredictable becomes the unbelievable, and suddenly the Gossett Team House training room is stocked with four injured quarterbacks, three with torn ACLs and two who are true freshmen.

The climax of the absurdity? Petty, who just two weeks ago began learning Maryland’s offense, will be the starting quarterback Saturday at home against Georgia Tech, because three of his predecessors now hobble around campus on crutches and a fourth only recently graduated to a knee brace.

Consider the reactions:

“Never in my life I thought a scout team linebacker would be the starting quarterback,” defensive lineman Isaiah Ross said. “It was definitely a shock. You don’t hear about this often.”

“I’ve never heard of anything like this. It’s unreal for me, but we have no choice but to step up and go with what we have,” wide receiver Nigel King said.

“It’s been surreal, seeing all these quarterbacks go down,” center Evan Mulrooney said. “You look at the big picture, and it feels like you’re in a movie. You can’t script this stuff.”

One gone, then three more

The injuries began slowly, in August during a preseason non-contact drill when incumbent starter C.J. Brown, a captain, tore his ACL.

Perry Hills stepped in for seven starts before an illegal block in the back shredded his ACL against North Carolina State. Caleb Rowe followed suit during Maryland’s penultimate play from scrimmage last weekend at Boston College, finishing the game until an MRI exam later revealed his own season-ending torn ACL.

“They’re like the Three Musketeers,” Caleb’s father, Dave Rowe said. Yet he was only referencing those three quarterbacks with torn ACLs, a list missing Devin Burns, a converted wide receiver who suffered a season-ending Lisfranc injury while playing quarterback for Maryland in the waning minutes against North Carolina State.

Seven days. Three injured quarterbacks.

And so the list of potential signal-callers dwindled, until Maryland was left with no scholarship quarterbacks, attracting the most national attention it has all season because of the situation’s absurdity, because the two only players listed on the depth chart at quarterback wear Nos. 31 and 87. The third-string quarterback is “to be determined.”

“No, I don’t feel jinxed,” Coach Randy Edsall said. “I think it’s one of those situations this year that we’re a little bit unlucky at the quarterback position. I think if you take a look historically at teams throughout the years, you’re probably going to lose maybe two to five players a year with knee injuries. For us it just happens that we lost our quarterbacks.”

Of course, that’s what makes this situation so baffling. Petty, who will continue to wear No. 31 when the Yellow Jackets arrive this weekend, was a three-year starter under Green at Eleanor Roosevelt, where he ran the triple option and zone-read schemes similar to Maryland offensive coordinator Mike Locksley’s system. He boasts a linebacker’s frame, sculpted like a truck, wears an eternal smile and spent all but the past week learning the Terps’ defense. But once Burns went down, Petty and tight end Brian McMahon, himself a former high school quarterback at Atholton High School, made the switch.

Now Petty, a left-handed bruiser who drew comparisons from teammates to Tim Tebow — at least in body type and playing style — will become the fourth quarterback in three games to take snaps from Mulrooney.

Petty’s big chance

Before 2012, the Terps had started just two true freshmen quarterbacks in team history, and none since 1999. Petty will be Maryland’s third true freshman starter this season.

“For him to start the year as a linebacker, then be the backup quarterback, then the next day it gets announced you’ll start?” said Ray Petty, Shawn’s father and the defensive coordinator at Howard University. “Just a perfect storm.”

Rowe, who brought the Terps back from a 13-0 second-half deficit against Boston College only to fall 20-17, felt healthy until he woke up Sunday morning and found his left knee stiff as a board. After visiting team trainers and undergoing a hasty MRI, Rowe phoned his father and broke the news. “I said, ‘It’s not funny, Caleb,’ ” Dave Rowe recalled. “I couldn’t believe it.”

Who would? Three quarterbacks suffering season-ending injuries was maddening enough, but at least a wiry gunslinger from South Carolina remained. Rowe endured similar growing pains as Hills did in his debut against William & Mary — each threw three interceptions — but still flashed drastic improvements during the second half, completing 23 of 42 passes in the game for 240 yards and two touchdowns, including a 66-yarder to Stefon Diggs that gave Maryland a 17-13 lead.

That came just one week after Terps fans held their breath while Hills writhed on the Byrd Stadium turf, his season ripped away when his left leg brutally jammed into the turf. Burns starred in the second half, opening up running lanes and breathing life into the Terps offense, while Rowe nearly finished the job before Brad Craddock’s potential game-winner smacked the left upright.

And so the Terps, still boasting a .500 record but on a two-game losing streak, officially enter “nothing to lose” territory, turning to another true freshman, one who long ago gave up dreams of becoming a college quarterback because he and his father figured that linebacker offered the best chance for greater playing time.

“He played quarterback in high school and I think he really feels like he’s a quarterback at heart,” Edsall said of Petty. “I know he’s looking forward to the opportunity to go out there and play, and we’re excited for him. He wants to play really, really well, so he can stay as a quarterback.”

He has to. The Terrapins have no choice.