Matthews was forced off during the Packers' 34-30 defeat to the Cincinnati Bengals two weeks ago after picking up a hamstring injury similar to the one that kept him out for four games last season.
However, McCarthy revealed that Matthews has progressed a great deal since suffering the injury and hopes that he will be able to continue that progress this week with a view to playing against the Detroit Lions on Sunday.
"I think Clay is better. He's made a lot of progress since coming off the field in Cincinnati. I'm hopeful that he'll be able to do more tomorrow. That's the plan," McCarthy told reporters after Matthews took part in limited practice.
The Packers are currently 1-2 for the season having had their bye last week.