Mike London and Virginia likely need to beat Ball State on Saturday to keep their bowl chances alive. (Andrew Shurtleff/AP)

If there was one positive to emerge from Virginia’s 14-3 loss at Pittsburgh last Saturday, it was a defense that couldn’t have left Coach Mike London happier. The turnovers and sacks he talked about creating all offseason had come to fruition, the bend-but-don’t-break philosophy of a year ago replaced by an attacking unit that appears to be one of the ACC’s best.

But a humbling setback also brought about reflection and frustration as to why his new defense seems to be so far ahead of his new offense. Lacking a definitive answer at this point, London has instead focused on a new strategy, one that doesn’t depend on his offense being more than serviceable against Ball State (4-1) on Saturday.

“If you have good defenses that can play well, then you don’t have to ask too much of your offense. Just don’t turn the ball over, convert some first downs and move the ball,” London said often this week. “Having a good defense can dictate a lot of things about how you call a game and what you do.”

It seems Virginia (2-2) has embraced the fact that its defense will be the catalyst if the program is to return to a bowl game this year. Even the personnel changes being initiated on offense this week can be traced back to the defense.

After impressing coaches going against the first-team defense during the preseason, freshman Eric Smith will start at right tackle and former All-Met Jay Whitmire (T.C. Williams) will move inside to right guard.

Meanwhile, at wide receiver, there was an open competition for playing time this week. London raved about freshman Keeon Johnson’s potential after some jaw-dropping catches in practice against a secondary that has held opposing quarterbacks to the second-lowest completion percentage in the country (38 percent) through four games.

But London also admitted the idea to use him came, in part, because of how successful freshman Max Valles proved to be last Saturday.

Valles grabbed the coaching staff’s attention ahead of the team’s season opener against BYU when he impersonated Cougars star linebacker Kyle Van Noy on Virginia’s scout team. So after dabbling at tight end and defensive end when he initially arrived on Grounds, Valles was moved to strong-side linebacker before the Oregon game.

Valles, who spent a post-graduate year at Fork Union in 2012, got his first start of the season Saturday at Pittsburgh and his skills rushing off the edge caused havoc. He finished with 2.5 sacks, part of a seven-sack day for Virginia’s defense.

But the Cavaliers’ offense hopes the days of relying on their defense will be short-lived.

“Obviously we had much higher expectations than to what we’ve performed so far. I don’t think anyone would disagree with that. Coach has every right to be frustrated and fans have every right to be frustrated,” senior offensive lineman Luke Bowanko said.

“We’ll have the confidence to know that we’ll probably be in every game we play in just because of how well they’ve been playing and they can keep points off the board. But the pressure is really on us to keep up our end of the bargain and have their back, because if they’re out there playing their [butts] off, we can’t go three and out a couple times in a row.”

Here are three more themes to watch as Virginia looks to close out its nonconference schedule with a winning record:

No pushover

Ball State may be a Mid-American Conference program that’s playing on the road Saturday, but it’s coming off a nine-win season that ended in the Beef O’Brady’s Bowl a year ago. The Cardinals’ lone loss in 2013 is a 34-27 defeat at North Texas, and they’re the only team in the country to score a touchdown on every opening drive this year. Quarterback Keith Wenning and wide receiver Willie Snead, whose father played wide receiver at Virginia and Florida in the 1980s, could pose issues for a Cavaliers secondary that has proven stout so far.

Wide open at WR

After watching his receivers drop 10 passes at Pittsburgh, Coach Mike London opened up the competition and allowed nine players to battle for playing time this week. Veterans Tim Smith, Darius Jennings and Dominique Terrell will still have prominent roles, but offensive coordinator Steve Fairchild has promised to use more receivers going forward. Bigger, taller options like sophomore Adrian Gamble and freshman Keeon Johnson could emerge, but London did not indicate what players would see the most snaps this week.

Identity crisis

The Cavaliers entered this season hoping to establish a power running attack, but those plans have come to a screeching halt through four games. Defenses have begun to stack the box against Virginia’s talented tailbacks, well aware quarterback David Watford is more of a threat with his legs than his arm at this juncture. But with the teeth of their ACC schedule fast approaching, the Cavaliers are running out of chances to uncover an offensive game plan that works.