GREEN BAY — Ryan Grant may very well end up playing against the Detroit Lions on Sunday at Ford Field, but the decision by coach Mike McCarthy and the medical staff to hold the Green Bay Packers' featured back out of practice Wednesday and Thursday wasn't just to give Grant's troublesome hamstring a rest.

McCarthy gave reporters the distinct impression after Thursday's practice that there's at least some chance that the Packers will hold Grant out of the game so he doesn't turn the hamstring injury into a season-long issue or, in the worst-case scenario, tear it and wind up missing several weeks.

McCarthy said Grant will go through "a portion" of practice today, then "we'll test it and we'll know where he stands Saturday morning."

After missing most of preseason during contract negotiations and with the hamstring problem, Grant ran 12 times for 92 yards against Minnesota Monday night, including a 57-yard run.

Asked if there's a real question of whether Grant will be able to go on Sunday, McCarthy replied, "That's probably a good question for (after today's practice). I know Ryan wants to play, and his communication will be that he'll want to play, I'm sure. But once he practices, the information from how he feels Saturday morning factors into it. And (team doctor) Pat McKenzie, (general manager) Ted (Thompson) and I will make a decision."

Health watch

Grant's backup, Brandon Jackson (concussion), took part in the jog-through portion of practice but joined center Scott Wells (back) and guard Josh Sitton (knee) with the rehab group after that. McCarthy said Jackson had yet to pass the post-concussion cognitive test doctors give.

If Grant can't go, McCarthy expects Jackson to be ready to start.

"I would be surprised if he's not cleared," McCarthy said. "I'm not a doctor, though."

Wells is expected to miss his second straight regular-season game after missing three preseason games. Sitton already has been ruled out. Cornerback Charles Woodson (toe) did not practice but should do so today, McCarthy said.

"I don't really ever question Charles when it comes to that stuff, because he's played with so many significant things in his short time here," McCarthy said. "We'll see."

Safety Aaron Rouse, who sprained an ankle in practice Thursday, and linebacker Brandon Chillar, whose back problems "flared up" on him, were added to the injury report.

Getting his kicks

Derrick Frost knew he wasn't going to be Mr. Popularity in the locker room upon his arrival.

When the Packers jettisoned well-liked punter Jon Ryan following the final roster reduction to bring in Frost, who'd been let go by the Washington Redskins, it not only came as a surprise to Ryan's former teammates, but there were a few who wondered what Thompson was thinking.

"Coming into it, I know these guys were friends with Jon," Frost said. "I know the new face isn't always the most welcome."

But after the way Frost punted in the Packers' season-opening victory over Minnesota on Monday night, he's a lot more welcome.

Frost averaged 45.2 gross yards and 42.6 net yards on five punts, with an average hang time of 4.06 seconds.

Only his last kick, with 1:51 left, disappointed him, because it was down the middle of the field and not to a sideline. Still, returner Aundrae Allison only managed 9 yards.

"He did execute just like we wanted him to," special teams coordinator Mike Stock said. "That first punt was an extraordinary punt. Textbook."

While Frost was happy to gain some of his teammates' confidence — "It's just good to show the guys on the team that I'm someone they can believe in," he said — the fact that his directional style meshes with Stock's philosophy is just as important.

"I think the way this organization sees me is the way I see myself, and I think that's a really nice fit," Frost said. "I'm not going to hit the ball ridiculously deep. I don't have the strongest leg in the league. And because of that, I'm going to be asked to do things that are situational — put it here, put it there, and just try to minimize the return yards."