"Without Ryan Grant, the Green Bay Packers' running game through three preseason games hasn't been the disaster it was last year at this time.

But despite the growth of Brandon Jackson in his second year, he isn't the runner Grant was the second half of last season.

Grant was back on the practice field on Sunday afternoon, recovered from the hamstring injury that kept him out of the first three preseason games. He'll make his 2008 debut in Thursday night's exhibition finale against the Tennessee Titans. He also missed the first week of training camp while his contract negotiations were finished, then strained his hamstring his second day back on the practice field.

Grant's return should give juice to a run game that's been pedestrian the last two games.

"I'd think so," said John Schneider, a Packers director-football operations. "He added juice to the run game last year when he came here."

Jackson started all three preseason games in Grant's place and is the team's No. 2 back because of improved decisiveness and strength in his play. But in the last two games, against San Francisco and Denver, he ran for only 29 yards on 11 carries (a 2.6-yard average).

The Packers didn't run the ball frequently - those 11 carries came in just more than four quarters of play, or a little more than a full game - and the starting offensive line deserves its share of the responsibility for those poor results.

But the Packers agreed this summer to negotiate a long-term deal with Grant for a reason - because he gives them a something no one else on the roster can. After rushing for 929 yards in the final 10 games last season, he finally agreed to a four-year contract earlier this month that will pay him $20 million, plus up to another $10 million in escalators depending on his performance.

Grant, 25, was worth the significant investment because he's a physical, 226-pound runner in his prime and is good for the Packers' zone-run scheme, which requires patience in reading blocks and decisiveness when a lane opens.

"He's a good fit for the zone scheme because he's such a strong one-cut guy," Schneider said. "He's an aggressive one-cut runner and he has excellent vision and he runs the ball hard. He's a bigger man, too."

Coach Mike McCarthy said Sunday he wants to see Grant get through the week of practice before determining how much he'll play against Tennessee. The best guess is Grant will play as long as the Packers' No. 1 offense is on the field, which probably will be only a couple of series.

The biggest issue is getting Grant as sharp as possible for the opener against Minnesota. Many teams give their top back only a few carries in the preseason to keep them from accumulating hits. San Diego doesn't play its top back, LaDainian Tomlinson, at all in the preseason. However, Grant also has missed extensive practice time because of the injury, so McCarthy probably will want him to get several carries a