Jerry Jones is excited about Cowboys' front seven

Dallas defenders surround 49ers running back Jerick McKinnon (28) during the first quarter at Levi's Stadium.Kelley L Cox-USA TODAY Sports

Dallas's defense showed a spark in the preseason opener. Will it light a fire for the regular season?

If you ask even casual observers what they saw from the Cowboys in their preseason-opener against the San Francisco 49ers last Thursday, they’re likely to mention intangibles on defense.

Although Dallas didn’t produce any sacks, and even though the 49ers scored 14 points in the last five minutes to win the game, the Cowboys effort in shutting out San Francisco for the first 29 minutes of action looked good.

There are several key pieces that give Dallas fans reasons to be optimistic. Jaylon Smith seems poised to have a breakout season and join Sean Lee as a play-maker at the linebacker level. Demarcus Lawrence, of course, is coming off a 14.5-sack season and shows no signs of slowing down. The secondary has shined in training camp under new coach Kris Richard.

Cowboys owner Jerry Jones will be the first to tell you he has the inside scoop on what’s going on behind the scenes in camp and he took time to praise the defense on Sunday.

“I like our numbers in our defensive front all the way across, both the down guys and the linebackers,” Jones said. “We’ve got a good group here and we’ve got numbers which means we can play with rotation.”

During his media session on Sunday afternoon, head coach Jason Garrett doled out one of his patented machine-gun list of compliments when asked about Lee returning to practice.

“He makes a ton of plays, he plays the right way,” Garrett said. “He’s an outstanding leader, has been for a long time. Coaches respond to him, his teammates respond to him. He leads by example first, but he’s not afraid to communicate and make sure everybody’s on the same page.”

Dallas will break camp in Oxnard, California, and return to DFW this week for a preseason home game versus the Bengals. While we’ll be seeing a limited cast of players — no reason to rush Sean Lee and others into action — that intensity and speed that showed up in last week’s game will be something to watch for again.