GREEN BAY, Wis. -- The only thing left for Mike McCarthy to do is officially name Jamaal Williams his starting running back.

Everything he has done and everything he has said indicate that the second-year pro will be the No. 1 back when the Green Bay Packers open the regular season on Sept. 9 against the Chicago Bears.

What happened to that running-back-by-committee approach the Packers coach suggested all offseason?

Don't forget, he left himself an out during an interview with ESPN back in June.

"But if one of them would emerge as that full-time guy, then you have to have that ability to adjust to that," he said at the time.

With all but one training camp practice completed and half the preseason schedule in the books, McCarthy might be ready to use that out, thanks to Williams.

"He's really poised to have a big year," McCarthy said this week. "Clearly without playing a game yet, I think we'll be talking about him at the end of the season as a second-year player that's made the jump."

With that, fantasy football fanatics might have been re-ordering the running backs on their draft board. Those scared off by the running-back-by-committee approach might reconsider Williams.

Williams ended last season as the Packers' No. 1 running back, though his 556-yard total ranked just 36th in the NFL and left him behind two quarterbacks: Cam Newton (23rd with 754 yards) and Russell Wilson (34th with 586). His 3.63-yard average was higher than that of only four backs who ranked in the top 35.

There's reason to think Williams will be more productive this season.

"Probably just [learning] the playbook and getting more comfortable with it," Williams said. "Once you get something comfortable and you know it, it's just easier for you. But when you don't know it and you're still thinking about things and you've got to study to try to remember -- when you're in the game, you don't have time to think about it."

Last season, Williams outlasted Ty Montgomery, who ended the season on injured reserve because of wrist surgery, and fellow rookie Aaron Jones, who twice sustained MCL sprains.

"Jamaal was a heckuva player last year for us as a rookie, and now he's just so comfortable," McCarthy said. "He's so consistent, and like most rookies that go through an offseason, he's had a chance to catch his breath.

"You remember these guys come out of college, they're training for their senior year. They come out of college, they're training for the draft. They get drafted, then they've got to shift their training. They go to an NFL club, they roll all the way into the longest season of their life. So then, boom, it's done. They catch their breath, but now you can see just the way he's developed physically."

The Packers got a scare last week, when Williams limped off the field with an apparent right ankle injury. He blamed Steelers linebacker Vince Williams for what he deemed a dirty play, but he avoided a serious injury. In fact, he was back on the practice field this week.

Jones missed most of the first three weeks of training camp -- plus the first two preseason games -- because of a hamstring injury. He might be the most explosive of the Packers' top three backs, but his early injury history and the two-game suspension (for violating the NFL's substance-abuse policy) he must serve to start the season have impacted his availability. Availability issues also have plagued Montgomery throughout his career, though he hasn't missed a practice this summer.

All three bring something different to the Packers, which explains why McCarthy initially leaned toward the committee approach, but the early reviews on Williams suggest that he is the No. 1 not only because he can run but also based on what he can do in the passing game as a receiver and blocker.

"I really like his versatility," offensive coordinator Joe Philbin said. "I think he can run the ball inside, he can run the ball outside, he appears to have a good blend of some power and strength, and he's got some shake in his body -- not just his dancing skills, which are renowned, I guess. And you know, he can pass protect. There's pictures of him in camp stepping up and picking up the blitz, a picture in the game last week where he can catch the ball in the flat and make somebody miss and run with good pad level.

"Again, I think he's displayed a good, varied skill set for that position, where you don't have to necessarily pigeon-hole him and say he's a power runner, he's an off-tackle runner, he's an inside runner. I think he's displayed the ability to give us some flexibility in a lot of areas."