GREEN BAY – Sitting half-dressed in the locker that he just recently was given, John Crockett is speaking to a reporter, and he can’t stop smiling.

Considering the usual cold-war atmosphere during the Packers’ media availability sessions, that alone suggests this undrafted rookie running back has a different sort of energy to him.

Then he shoots his rolled-up ankle tape into a trash can 20 feet away, makes the shot, yells "Buckets!" and, while still maintaining all modesty and team-first truisms, laughingly says his nickname is "Taz" – as in the Tasmanian Devil. That’s when it’s certain: John Crockett has a different sort of energy to him.

It’s that vibe – his unflagging enthusiasm, eagerness to learn and frequent outbursts of excitement – that got Crockett promoted from Green Bay’s practice squad to the field in Detroit, where he rushed for crucial yardage in a must-win game last week.

The fast pace of good news – he was playing against the Lions just hours after being signed to the active roster – suited Crockett. And the Packers’ euphoria after the wild, Hail-Mary ending was fitting for his debut, though he probably would have been just as high-spirited, no matter the result.

"I’m just being myself; that’s how I practice, that’s how I play, everything," Crockett said of his demeanor. "I’m an up-tempo guy, and the team was looking a little down in the dumps. Coach gave me the go and the offensive line was able to make some holes and I was able to run through them and I guess give a little spark.

"But at the end of the day, I was just being myself. I was just being Taz."

Lively and lighthearted, Taz is most importantly fresh – both in terms of his legs (Crockett played seven offensive snaps last week; Eddie Lacy and James Starks have combined for 764 this season) and his attitude (sequestered in the practice-squad room most of the year, he hasn’t endured the doom-and-gloom daily questioning the rest of the team has over the past month).

Crockett wants to be here – not just in Green Bay, which he said is exactly like his college town, but in this locker room, next to fellow rookie Aaron Ripkowski and near Eddie Lacy, the embattled veteran whose playing time he took last Thursday.

After that game, head coach Mike McCarthy, not one to gush, was almost effusive in his praise of the 23-year-old running back.

"It’s right in front of him," McCarthy said. "He's doing a good job. He got a good opportunity up in Detroit, went the wrong way on a run and still had a helluva run. He brings a lot of excitement. I’m really happy for John, and the opportunity he’s been given, but he’s going to have to compete to get up on the active roster."

Added quarterback Aaron Rodgers, "I thought Crockett came in and gave us some good runs. I was really impressed by him. Being a practice-squad guy and then next thing you know he’s on the active roster, getting some carries, he’s making the most of his opportunities. So I’m happy for him."

Before making the active roster and getting carries, before being on the practice squad, before training camp and before he went undrafted and got a $5,000 signing bonus from the Packers (comparatively, seventh-round picks received about 10 times that amount), the 6-foot, 216-pound Crockett was just a relatively big man on campus in the Green Bay-sized town of Fargo, N.D.

Initially recruited to North Dakota State out of Minneapolis to play both football and basketball ("Buckets!"), the high-school point guard said hoops was his first love. On the hardwood is where he got the nickname Taz, during a tournament in third grade when he was playing feverishly, and he still has confidence in his game.

"I told Quinten I’m a little bit better than him," Crockett said of rookie cornerback Quinten Rollins, who played four years of college basketball at Miami (OH) before joining the football team.

Crockett went the opposite way, choosing to focus on the gridiron because he was told he might have a career on it. That advice proved prescient, as he rushed for at least 1,000 yards in three straight seasons, set school records for all-purpose yards (2,419) and rushing yards (1,994) as a senior, and played on three FCS national championship teams.

Despite not being drafted, Crockett was thrilled to sign in Green Bay, which he said reminded him a lot of Fargo – the size, the team colors, the football obsession of the fans – and was "one of the places that actually gives you a shot."

Thoroughly un-culture-shocked in Titletown, Crockett got his shot during training camp and, though he was beaten out for a roster spot by fellow undrafted rookie Alonzo Harris, did enough to earn a berth on the practice squad. Since September, he’s endeared himself to teammates and impressed coaches with his hard work in practice – and his positivity at home games.

"It just puts a smile on my face when I think of Crockett," McCarthy said. "You come off the field here at Lambeau, he’s the first guy in the tunnel and greets the team. He’s got unbelievable energy. He puts a lot of time in. He’s got his nose in his playbook, the way it should be. So there’s just a lot there that’s been going on really since training camp."

When the Packers released Harris after he and Lacy missed curfew the night before the game against the Lions, Crockett was already in Detroit – he’d been named to the travel party as one of two practice-squad players of the week – and ready to seize his opportunity.

Starting the second half in the backfield, he only had five carries in the game. One was for no gain and another was a four-yard loss, but gains of 10 and 12 yards showed the burst that was on display in the preseason, when Crockett was the Packers’ leading rusher. It was a glimpse, and it gave the stalling Packers offense life.

When you ask teammates about the charismatic Crockett, a couple words come up often.

"I liked his energy, I liked the way he came out and played really hard," fullback John Kuhn said Wednesday of the rookie’s performance in Detroit. "He does the same thing every day that he did in the game. We needed a spark and he provided that."

Ripkowski, another fullback and a member of Crockett’s draft class, echoed the veteran’s sentiment. "He’s always a guy that’s full of energy, and it’s awesome to have around because he gives us a spark."

It would seem then that his energy provides some sort of spark.

Individually, Crockett said he has no specific goals this season, only to contribute to the team winning. He’s not treating this week differently than any other, even if the stakes are higher.

"When you’re on the practice squad, you know at the end of the day you’re probably not going to have a tremendous impact on the game, or you’re not going to be able to, let’s say, mess up," Crockett said. "Now, you’ve kind of got more weight on your shoulders because you want to carry over what you did last week. You’re still going to go out and play football, still play your game, but it’s a little bit more pressure now.

"But that’s the game you play. You wouldn’t be here if you weren’t ready for this. So that’s the mindset you have to have – it’s just another day at the office."

The Packers, who are 1-0 with Crockett on the roster, can be glad that Taz’s office is the football field.