GREEN BAY, Wis. -- For Aaron Jones, it’s how you start and how you finish.

Consider what the Green Bay Packers' second-year running back did in his first two games:

• His first touch in Week 3 against the Redskins turned into a 10-yard run on the Packers’ third series.

• His first touch in Week 4 against the Bills turned into a 30-yard run on the final play of the first quarter.

• His first touch in the second half against the Bills turned into an 11-yard run on the first play of the third quarter.

All three drives turned into points.

Jones still isn’t the starting running back; he’s likely to remain No. 3 on coach Mike McCarthy’s depth chart this Sunday at Detroit. But for now, he’s the perfect tone-setter to start a drive.

“I want to be a spark plug,” Jones said. “Like a spark-plug player, and just create momentum. In games, it’s momentum. You see it every week in and week out. Once a team gets momentum, it just carries over and keeps rolling.”

At some point, Jones’ role might increase. But after he missed most of the preseason with a hamstring injury and the first two games of the regular season because of a suspension for violating the NFL’s substance-abuse policy, McCarthy doesn’t want to overwork Jones even if he’s the Packers’ most productive back.

His 6.3-yard average per carry would rank third among all NFL backs if he had enough attempts to qualify, but he has carried only 17 times. Four of his 17 carries have gone for 10 yards or more. He also has an explosive gain in the passing game, with a 17-yard pickup on a screen pass against the Bills in Week 4, a play on which he showed remarkable balance to spin out of a tackle.

“Sometimes, I’m like, ‘I don’t know how I did that,’” Jones said of the spin move.

It’s not like this is a fluke. Jones averaged 5.5 yards on 81 carries last season as a rookie.

But no one knows yet if he can do it over the long haul.

He began last season behind Ty Montgomery and Jamaal Williams. His first start came nearly a year ago, on Oct. 8 at Dallas, where he rushed for 125 yards on 19 carries. He added a second 100-yard game -- 131 on 17 carries two weeks later against the Saints -- but a pair of knee injuries limited him the rest of the season.

Still, Jones had his moments. His only carry in the Dec. 3 victory over the Buccaneers was the game winner: a 20-yard touchdown in overtime.

It might explain why, for now, McCarthy prefers to keep Jones in a complementary role with the hope that his most explosive back will be fresh instead of worn down late in the season.

“That’s ideal,” McCarthy said. “That’s a big-picture focus. We understand there’s going to be about 1,100 snaps in the season and you want to be playing your best football at the end of the year, and running the football is a big part of playing at Lambeau Field. Yeah, definitely, the goal is to have all three of those guys throughout the season.”

So far, Jones has said all the right things about his role behind Williams and Montgomery and believes there’s a benefit to it both now (to glean insight from them during games) and long term (to stay fresh). When Williams or Montgomery comes off the field, they’re able to give Jones a feel for what the defense might do.

Jones also claimed he doesn’t allow himself to imagine what he could do with 17 or more carries a game -- something that has happened only twice in his young career.

“I don’t,” Jones said. “I mean, I just know I’ve just got to be ready when my time is called, and if you look in Carolina a couple years back, they had two backs. And I feel like if we have three backs here, it just helps you stay healthier the whole season and prolongs your career.”

Meanwhile, the Packers can continue to use Jones early on drives to set up plays for Aaron Rodgers later -- something that can deflate defenses.

“It’s definitely [deflating] when someone starts a series like that,” Packers linebacker Blake Martinez said. “Especially when you have the other Aaron on our team, when you have a guy that’s going to run the ball and get 10 yards right off the bat and all the other teams are scared about is the pass game, it has to be like, ‘Oh no.’”