While B.J. Raji has accelerated directly into the starting mix, the Green Bay Packers other first-round draft pick remains stuck in first gear.

Outside linebacker Clay Matthews hit another roadblock on Wednesday, when his problematic hamstring forced him to drop out of practice in the earlygoing.

Matthews sustained the injury in the Packers first organized team activity practice on May 27 and didnt practice at all last week. He opened Wednesdays practice as the No. 2 right outside linebacker but was on the sideline getting extra stretching before the first team (11-on-11) period.

The injury isnt believed to be significant, but the Packers likely will proceed cautiously through at least the remainder of OTAs with a rookie they believe can be a major contributor this season.

Hes a big, big, strong, fast kid guy, dude, whatever, fellow linebacker Brandon Chillar said of Matthews, the 26th overall pick out of Southern California.

I think hes got a lot of talent. Hes been hurt, so we havent got to see too much of him, but hes definitely showed some flashes, and obviously, hell probably continue showing those as hes on the field more.

Nose tackle Ryan Picketts return after missing last week for personal reasons meant Raji, the No. 9 pick, was back to playing left end in the base defense and defensive tackle in nickel, both with the first team.

Asked for his early impressions of his two top rookies, coach Mike McCarthy said, They look like they are going through their first OTA.

Every day is a learning experience as far what defensive scheme we have in. (Coordinator) Dom Capers and the defensive staff have been installing a lot of defense, getting all of their different defensive personnel groupings in. Raji has done an excellent job, and Clay is kind of fighting through a hamstring.

Progress report: The installation of the Packers new 3-4 defense will be complete by the time OTAs end next Thursday.

The mandatory minicamp June 22 to 24 is slated for review, and only then will the Packers begin to get a true sense of how things are coming together.

McCarthy addressed the team on Wednesday about eliminating missed assignments but said hes been very pleased with what I have seen so far from the defense.

The unit continues to work without three likely starters recovering from surgery right end Cullen Jenkins, safety Atari Bigby and mack linebacker Nick Barnett as well as Pro Bowl safety Nick Collins, who has skipped most of the offseason program and wants a new contract.

Of course, the longer you play it, the better you get, Pickett said, but I think were going to shock people on how good we play it the first year.