Sometime in the coming months, the Green Bay Packers will take a long look at all aspects of the running game to figure out why Ryan Grant's numbers took such a nose dive this season.

Though he ranks ninth in the NFL with 1,097 rushing yards, Grant's per-carry average has plummeted from 5.1 last season to a shaky 3.7, a figure that's trended downward the past two weeks with rough outings at Jacksonville and Chicago.

It doesn't mean Grant's surprising 2007 season was a fluke, nor that he's primarily responsible for the drop in efficiency this season. However, the numbers have changed so dramatically the issue merits further examination.

"There's a drop-off there that's concerning to everybody," offensive coordinator Joe Philbin said on Thursday.

Statistically speaking, it's easy to trace the drop.

After taking over as the primary back last season, Grant had at least one explosive run (12 yards or more) in all 10 games and 20 total -- the same number he's had in 15 games this season.

Those 2007 runs were more explosive, too.

His long run this season was a 57-yarder in the opener against Minnesota, and he has only one other run longer than 22 yards.

Last season, he had touchdown runs of 66 and 62 yards, plus nine others of 23 yards or more. Coupled with an increase in "minus" runs -- he's had 35 for a net loss of 83 yards this season compared to 22 for 35 yards in 2007 -- it's little surprise his numbers have fallen so far.

Why it's happened is more complicated.

First, there was Grant's contract situation, which kept him from participating in offseason practices and the first week of training camp. Only days after signing a four-year contract that could pay him as much as $30 million, Grant injured a hamstring and ended up playing only one snap in the preseason.

With coaches urging him not to "open it up" because of concerns about reinjuring the hamstring, Grant rushed for only 186 yards on 55 carries (3.4 average) in the Packers' first four games. His workload increased in October, but not his efficiency or explosion -- in wins over Seattle and Indianapolis, he carried 64 times but gained just 195 yards (3.0 average) without a run longer than 17 yards.

After strong showings the next three weeks, Grant has gained better than 3.7 yards per carry only once. The past two games have been Grant's worst since September -- 21 carries for 56 yards (2.7 average) at Jacksonville and 25 for 61 (2.4) at Chicago, a team he gouged for 145 yards on 25 carries only five weeks earlier -- and renewed scrutiny of his qualifications as a No. 1 back.

Among the criticisms lobbed at Grant is he doesn't break enough tackles and tends to take on contact instead of trying to avoid it, though the latter isn't a surprise for a back who stands 6-foot-1 and weights 226 pounds. Running backs coach Edgar Bennett has focused on getting Grant to more consistently keep his legs moving in traffic, break arm tackles and attack second-level defenders. Grant showed what he can do in that regard by running over Bears safety Craig Steltz while taking a screen pass 17 yards for a score Monday.

"His style is more physical, attacking, downhill runner," Bennett said. "He's not a scatback -- he's a big guy, and we love that about him, because when you're in these type elements, you want a big guy carrying the football, running downhill with enough wiggle to make that guy miss -- he's shown that in the past -- and have the speed to finish his runs, to be explosive.

"One of his strengths always is his vision, and that hasn't changed. He sees it the way he's supposed to see it. He's using a good aiming point. ... His initial read has been good -- certainly up in the 90 percent range if you were grading him over the course of the season."

Grant also has shown improvement in ball security, which seemed it might become an issue. He had two fumbles in a playoff game last year against Seattle and three in the first seven games this season, but hasn't fumbled since.

The increase in Grant's runs for loss -- and the yardage being lost -- is one indicator blocking has played no small role in his struggles. The past two weeks, Grant has had nine minus runs, including basic zone right plays that lost 5 yards on the first series at Jacksonville and 6 in the fourth quarter at Chicago.

"There's some major problems if you've got somebody 5 yards deep in the backfield, and that's certainly not related to the back," Philbin said.

There are other factors to consider, not the least of which is game situations. Opportunities in the running game are different for a team that's 13-3, as the Packers were last season, and a team that's 5-10.

But it's not out of the question that, as they analyze the running game in the offseason, the Packers might reconsider Grant's status as the featured runner in a one-back system. In addition to an intriguing backup in Brandon Jackson and a talented No. 3 in DeShawn Wynn, the Packers have a top-10 pick in April's NFL draft and plenty of salary-cap space to delve into free agency.

By rushing for 1,000 yards this season, Grant increased his base salary for 2009 from $750,000 to $1.25 million, and it could go up to $2.25 million if he hits the 1,250-yard mark by gaining 153 yards in Sunday's finale against Detroit. He also is due a $2.75 million roster bonus in March and can earn a workout bonus of $250,000.

Asked this week whether he feels he's proven he should be the No. 1 back, Grant said: "I hope so. I don't think I've done enough on my end (because) my expectations are high. But I feel like they still have the confidence in me."

That includes Bennett.

"Honest to goodness, I believe he can be in that next tier of guys that are special," Bennett said. "He's shown in the past, as far as turning a 10-yard gain into a 50-yard gain. He's shown that in the past ... but we need to be more consistent at those type runs."