GREEN BAY, Wis. -- Davante Adams huddled the Green Bay Packers receivers before their first drill of Wednesday’s practice. And by receivers group, that meant him and the three rookies -- fourth-round pick J'Mon Moore, fifth-rounder Marquez Valdes-Scantling and sixth-rounder Equanimeous St. Brown.

That could be all Aaron Rodgers has on Sunday in Detroit given Randall Cobb’s hamstring injury and Geronimo Allison's concussion.

So Adams, the veteran of the group, wanted to make sure the rookie trio knew what was at stake.

“That he’s counting on us,” Valdes-Scantling said after practice. “We’ve got two starters down right now and we don’t know the timeline of their return, so they’re counting on us to go out there and not have any fall-off from what they were doing to what we’ve got to do.”

Even Adams popped up on the injury report because of a calf, and coach Mike McCarthy said that Adams did not finish practice and won’t go on Thursday. Neither will Cobb or Allison, leaving the three rookies by themselves.

To hear Valdes-Scantling tell it, Adams wanted to “make sure that you guys are locked in -- you’re going to get a lot of reps today. The older guys usually don’t practice a lot on Wednesday, so it’s mainly for the younger guys so we can get the experience that we would need so when it comes to Sunday, we’re prepared.”

Of the three rookies, only Valdes-Scantling has played any significant snaps and that only came in Sunday’s 22-0 win over the Bills because Cobb was inactive. The fifth-round pick played 54 of his 74 season snaps against the Bills. Moore, a fourth-round pick, played all 11 of his snaps this season against the Bills after Allison left with a concussion and didn’t have a ball thrown his way. St. Brown, a sixth-rounder, has not played from scrimmage yet, appearing only on two special-teams plays in Week 1.

Valdes-Scantling has the only two receptions among the rookies, for 41 yards. Most of it came on a 38-yard go route in the fourth quarter against the Bills in which he showed off his 4.37-second speed in the 40-yard dash. That came after he made a mistake on a route on a third-quarter fourth-down play in which he failed to adjust properly, leading to an incompletion and a turnover on downs. It could have been much worse, however, because that throw went right through the hands of Bills cornerback Ryan Lewis, who would have turned it into a pick-six.

It drew a stern look and a talking-to from Rodgers, who wouldn’t reveal what he said other than: “Probably wasn’t real friendly.”

Rodgers was far more forgiving on Wednesday.

“Well, I wanted to get him another chance,” Rodgers said. “The first route is a route that Jordy [Nelson] and I used to throw in our sleep, so you can’t necessarily expect to be on the same page right away in a situation like that. So I came back to him, he had a go route and just ran by the guy and it was a nice play for him. Any young receiver needs kind of that big play to get going. Up 19-0 at that point, it was a good opportunity to go back to him and give him a chance.”

If the three rookie receivers have to play extensively on Sunday at Detroit, it will come less than two months after Rodgers ripped the group in training camp following a substandard practice.

“I think we’ve grown a lot,” Valdes-Scantling said. “We’re still learning. We’re still growing, but from that day to now, there’s been a lot of progress made, a lot of plays have been made, a lot of trust has been earned. I think that’s something we had to do over time.”

It also will be a chance for Moore to show he’s fixed his issues with dropped passes that plagued him during the preseason and training camp.

The Packers had five drops in Sunday’s win over the Bills -- three by Allison and one each by tight ends Jimmy Graham and Lance Kendricks.

It’s also possible the Packers could rely more on their tight ends and play less with their standard three receivers on the field.

Or there’s always the possibility that receiver-turned-running back Ty Montgomery could line up on the perimeter.

But if it is a heavy dose of the three rookies, Rodgers needs them to be ready -- a point Adams underscored.

"I think we’re all always focused, [but] it’s always good to have a reminder, especially from a guy who’s one of the best in the league saying he’s counting on us because we help this offense roll," Valdes-Scantling said. "You can’t just have one guy doing it, especially when you have a guy like [Adams], who’s going to attract double-teams, so we’ve got to be able to help our quarterback out and help this offense out by making plays."