McCarthy: Abbrederis has concussion

Green Bay Packers coach Mike McCarthy spoke to the media on Friday following practice. Here are some highlights:
On wide receiver Jared Abbrederis' absence from practice:
He suffered a concussion yesterday. He's going through the protocol.
On limiting left guard Josh Sitton's reps:
Just being smart with him. He's played a lot of football here. It's smart to give younger players opportunity.
On the two practices so far:
The structure and drill work makes for things we've done right. As far as getting the tempo and pursuit and cover, mechanics, our field guys do a tremendous job. I don't think you recognize how organized these practices are. First two practices have gone well. Effort is excellent. Off to good start.
On quarterback Matt Blanchard:
I think Matt Blanchard is progressing well. It was important today to get everyone involved in the no-huddle drill. Once we evolve that, it'll give us some information on start.
On the defensive backs:
I thought the DBs did very well. They got their hands on the ball a bunch. That's what you're looking for.
On Saturday's first padded practice:
You don't want to dial guys back at all. You want intensity to be where it needs to be. You have to address player safety.
On the half-line drill:
We'll do it in training camp. It's an inside-run period. Drill you do nine-on-seven, I didn't like that because I'm an offensive coach. I always preferred team run. That's why we do team run. Receivers have to block. DBs have to get off blocks. Get into combination periods, group periods.
On linebacker Clay Matthews' workload:
Workload, it hasn't changed. He's always worked this much. Where he's working has changed. He spends a lot more time at the inside linebacker position. Played his whole career at outside linebacker.
On using wide receiver Randall Cobb on punt returns:
Absolutely. Randall Cobb, at the end of the day, you're designing plays and looking at distribution of opportunities.
On rookie guard Matt Rotheram's absence from practice:
Looking at his ankle.