GREEN BAY, Wis. (AP) - Hold on to the ball. Chip the pass rusher on the inside shoulder. Track his offensive linemen's helmets to find the holes.

So many tasks to pick up for the Packers' Eddie Lacy. It's on-the-job training for the rookie running back.

There's always room for improvement. It was my first (game). I did some things well and there (are) some things I have to clean up,'' the rookie from Alabama said Wednesday.There's always little details in everything.''

He's heeding to the lesson plan administered by coach Mike McCarthy - work on the little things, the details - and good things should follow for Green Bay's running game.

It was a so-so NFL debut for the 5-foot-11 Lacy, whose 230-pound frame seems suited to grinding out yards in the black-and-blue NFC North. He got off to a slow start with four yards on five carries, and lost a fumble at the Packers 13 that set up a San Francisco touchdown in the 49ers' 34-28 win last week in the season opener.

Lacy got benched after the turnover but regrouped in the second half. He finished with 14 carries for 41 yards and his first career touchdown, a 2-yard score that briefly gave the Packers a four-point lead in the fourth quarter.

Safe to say, that milestone ball is tucked away at Lacy's home.

``It's on my bed. I sleep with it,'' Lacy said, drawing chuckles.

The Packers took him in the second round of the draft to beef up the running game and add more balance to an offense that boasts 2011 MVP Aaron Rodgers. With the Crimson Tide last year, Lacy often looked like a pinball bouncing off defenders en route to 1,322 yards rushing and 17 touchdowns, finishing with the highest yards-per-carry average (6.8) in school history.

Of course, Lacy still had first-game jitters. Almost every rookie does when he first steps on to the field at the next level. His next career landmark arrives Sunday, when the Redskins visit Lambeau Field for the Packers' home opener.

Nerves aside, first-year guys are often counted on to contribute quickly at Green Bay, which abides by a ``draft and develop'' mantra. A right knee injury knocked DuJuan Harris from atop the depth chart for the season, putting more of a load on Lacy.

Can't be a rookie anymore,'' All-Pro guard Josh Sitton said.It's time to go.''

Rodgers was in midseason form in the passing game last week after throwing for 333 yards and three touchdowns. Green Bay scored on four quick, but long drives, including lengths of 80 and 76 yards.

But aside from the two turnovers, five three-and-outs also hurt. A couple penalties brought back nice runs.

Offensive lineman Marshall Newhouse said the front five is going to keep at it in ``playing physical and hit people in the mouth. Things will open up for us.''

Becoming more consistent on drives has been a topic of discussion, in part to help the defense, too, Rodgers said.

So it was the good with the bad ... One first down a series is kind of the bare minimum for us,'' he said.If you do that you can semi-change field position.''

Getting better on the run would help. But while the Packers expect more production, they also know that Lacy is learning on the job.

``It's the little things. Eddie's no different than any other rookie that comes into an offense with a veteran quarterback that has the ability to do a lot of things at the line of scrimmage,'' coach Mike McCarthy said.

``I don't care who you bring in here, all of our new guys who are first- and second-year players are really challenged at this time of year. I like what I see. He's off to a good week.''

Notes: Sitton sat out practice with a sore back he said he aggravated on the long flights to and from San Francisco. His availability for Sunday is uncertain. ``I'm an offensive lineman, I mean back problems are going to happen,'' Sitton said. The Packers could move Don Barclay to left guard and slide Newhouse in at right tackle. ... TE Jermichael Finley sat out with a sore toe he said he injured after 49ers LB Patrick Willis fell on his heels during a drag route. He said he plans to play Sunday ... S Morgan Burnett (hamstring) returned to practice on limited basis, while LB Nick Perry (neck) was a full participant. CB Casey Hayward remains sidelined with a hamstring injury.

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