Baltimore Sun reporters Jeff Barker and Don Markus and editor Matt Bracken weigh in on the three biggest topics of the past week in Maryland  sports.

How much can linebacker-turned-quarterback Shawn Petty realistically do in his first start as a fill-in for the Terps against Georgia Tech?

Jeff Barker: It’s really quite an experiment, isn’t it? Albeit a necessary one after four quarterbacks were lost to injury.

Take one linebacker who was a high school quarterback and try to gauge just what he can handle.

It’s all about finding the right balance – how much can you teach him so that Maryland has some variety in its offense? You don’t want to pile too much on his plate in such a short time.

I anticipate that Petty will have some success running the ball on the option. He’s big and strong, and Georgia Tech won’t have any college-level video on him.

“Maybe we have to adjust on the fly,” Georgia Tech coach Paul Johnson said this week.

What I don’t know is how much Petty will throw. I’m just guessing here, but it makes sense that Maryland will try to get him started with some basic screens. Hello, Stefon Diggs.

Screens and short routes would have the dual benefit of allowing Petty to gain some early confidence while getting the ball into the best playmaker’s (i.e., Diggs) hands.

Among the issues created by all the quarterback injuries is that they complicate Maryland’s efforts to increasingly make Diggs a centerpiece of the offense. I sensed that Diggs had chemistry with the last quarterback, Caleb Rowe, who was injured in the Boston College game last week.

Of course, I’m not the only one who will likely anticipate some early screens to Diggs. Georgia Tech coaches may be looking for that as well.

Psssst, maybe the Terps should fake a short route early and allow Petty to let one fly deep. If only to keep the defense guessing.

If Maryland is forced to turn to its sixth-string quarterback, what can be expected of Brian McMahon?

Matt Bracken: You may recognize this question from last week’s Terps Trio, only with “sixth-string” replacing “fifth-string” and “Brian McMahon” instead of “Shawn Petty.” The topic seemed a bit ridiculous last week, but then Caleb Rowe tore his ACL and all of a sudden it actually became relevant to analyze Petty’s past as a high school quarterback and project how he might fare for Maryland if pressed into action.

The freshman linebacker from Eleanor Roosevelt is a tough, physical player, and I’m sure Maryland offensive coordinator Mike Locksley will take extra precautions with his game plan to minimize the threat of injury. But Barker has that covered above. So at the risk of being a huge jinx again, here’s what we know about Maryland’s newest backup QB.

McMahon guided Atholton to a Howard County championship one year ago. As a 6-foot-4, 210-pound senior, McMahon threw for 1,289 yards and 13 touchdowns, while rushing for 772 yards and eight scores. Despite completing better than 60 percent of his passes, McMahon had almost no college interest at quarterback.

Several Ivy League schools liked McMahon as an athlete, and he eventually landed an offer from Colgate. But ultimately it came down to Johns Hopkins and Maryland, which wanted the 3.9 student as a preferred walk-on at tight end.

“Athletically, I think he’s a Division I athlete,” Raiders coach and former Terps offensive lineman Kyle Schmitt told The Sun last February. “And I told him if he played tight end for us, I really think that he would be at least a 1-AA type of kid, or a Division I type of athlete. That wasn’t what was best for us. But he runs a 4.6, he power-cleans 300 pounds, bench presses 300 pounds. He’s only going to get bigger and stronger. I really think he’s got a great upside as an athlete. It was the best move for him.”

Since he has enrolled, McMahon has gained 20 pounds, according to his UMTerps.com profile. From a physical standpoint, he probably wouldn’t look out of place under center during an ACC game.