Northwestern has been plagued by issues with quarterback play this season. That’s plainly obvious.

But put yourselves in the shoes of Purdue for a moment. Because of injuries to their top two quarterbacks, the Boilers will start third-stringer Aidan O’Connell on Saturday against Northwestern. What’s more, O’Connell is a walkon sophomore who will be making his first career start.

Yet, even after losing incumbent starter Elijah Sindelar in Week 2 and backup Jack Plummer last week, Purdue still ranks second in passing in the Big Ten (301.6 ypg) and is scoring a respectable 24.6 points per game.

That stands in stark contrast to Northwestern, which is languishing in last place in the Big Ten in passing (124.3 ypg) and last in the entire nation in scoring (9.8 ppg).

It all makes you scratch your head and wonder how the Boilers’ quarterbacks have performed as well as they have, especially while Northwestern’s have floundered so spectacularly.

We asked Tom Dienhart, who covers Purdue for GoldandBlack.com, what the Boilers’ secret is.

“Credit (head coach) Jeff Brohm,” said Dienhart, who previously worked for the Big Ten Network. “He has further enhanced his ability to work with quarterbacks, as this season has put his acumen to the ultimate test.

“None of the signal-callers are five-star talents, but Brohm is good at developing packages to fit the skill-set of each guy.”

You probably won’t hear words remotely like those from any media members about Northwestern head coach Pat Fitzgerald or offensive coordinator Mick McCall this season for their handling of their quarterbacks.

To be fair, it seems like the Wildcats’ problems stem more from execution on Saturdays than game planning or coaching throughout the week. But still, if this season has been an "ultimate test" for the coaches, you can’t give them a passing grade.

The Wildcats have certainly endured a string of misfortunes at QB. They lost TJ Green, by far their most experienced signal-caller, for the season in the opener against Stanford. Hunter Johnson started the first four games but then sat out for three weeks as he supported his mother in her battle against breast cancer. The Wildcats, like the Boilers, were forced to play their third-string quarterback, and Aidan Smith started the last four games.

But Purdue has had to absorb more than its share of hits this season at the team’s most important position, too.

The Boilers began the year feeling as solid at quarterback as just about any team in the Big Ten, with Sindelar, a fifth-year senior with nine career starts, at the controls. He got off to a blazing start in Brohm’s pass-happy offense, throwing for 931 yards, with nine touchdowns and three interceptions, as Purdue split its first two games.

But Sindelar suffered a concussion in a Week 2 win over Vanderbilt, and Jack Plummer, a redshirt freshman, made his first career start in a loss to TCU the following week. Sindelar came back the in Week 4 against Minnesota and disaster struck when he broke his clavicle in the first half. (To compound that stroke of bad luck, star receiver Rondale Moore was hurt on the same play and has yet to return, either.)

Plummer was forced back into duty and filled in admirably as the Boilers dropped decisions to Minnesota and Penn State.

But Plummer really found his mojo against Maryland, completing 33 of 41 passes for a school-record 80.5% for 420 yards, with three TDs, in a 40-14 win. To put his outing against the Terps in perspective, that’s one more touchdown than Johnson and Smith have, combined, in eight games.

Plummer went on to start the next three games, but last week he hurt his ankle midway through the fourth quarter against Nebraska. With the Boilers trailing 27-24, most coaches would hope that their third-string QB can just catch the snap from center.

But O’Connell rose to the occasion. In his second series, he went 6 for 6 for 62 yards through the air as David Bell scored the winning touchdown on a nine-yard run with 1:08 left in the game as the Boilers posted a 31-27 win.

Looking at the big picture, there are some similarities between Purdue’s and Northwestern’s QB situations.

The Wildcats lost their fifth-year senior in the opener, though Green was a walkon with limited playing time and not a proven veteran like Sindelar. Plummer, like Johnson, is in his second year in the offense, though Johnson is a year older and, as a former five-star prospect coming out of high school, has a better pedigree than Plummer, a three-star. Smith, a redshirt junior scholarship QB, would also seem to have an edge over O’Connell, a second-year walkon.

Purdue, however, has gotten far more production out of its two QBs than Northwestern has gotten out of their pair. While the Boilers throw the ball much more frequently than the Wildcats, if you take the numbers from the four quarterbacks that have played the most over the last several weeks for each team – Plummer and O’Connell for Purdue, Johnson and Smith for Northwestern – they are pretty comparable. Plummer and O’Connell have attempted 31 more passes than Johnson and Smith, but their throws have generated far more offense.

Plummer and O’Connell: 159-264, 1,736 yds, 6.6 ypa, 60.5%, 12 TD, 8 INT

Johnson and Smith: 110-233, 932 yds, 4.0 ypa, 47.2%, 2 TD, 10 INT

That’s a striking difference. Even if you throw out the raw numbers like yards and TDs because the Boilers rely so much on the passing game, Purdue’s QBs are still far more accurate and efficient Northwestern’s. That’s why both Plummer’s and O’Connell’s efficiency ratings (124.0 and 134.0, respectively) dwarf Johnson’s (78.0) and Smith’s (73.5).

Both Purdue and Northwestern are in the midst of disappointing seasons, caused in part – in Northwestern’s case, a much larger part – by suspect quarterback play.

The Boilers have lost two of their last three games, but they have been competitive, getting outscored 77-57, an average of about a touchdown per game. Northwestern, conversely, seems to be allergic to the end zone and back-sliding: the Wildcats haven’t scored a touchdown in 13 quarters and have been outscored 106-6 in their last three games.

The bottom line is that, despite all of the adversity at quarterback, Purdue’s offense has managed to tread water. The Wildcats' offense, on the other hand, seem to be sinking like a stone.