Erik Gustafsson and Travis Hamonic being shopped? Why would Detroit willingly trade away depth?

The Detroit Red Wings are off to a hot start, with a lot of young players. This means though that Erik Gustafsson, Travis Hamonic and Justin Holl have been pushed out of the lineup, and into Grand Rapids. Dave Pagnotta now reports Detroit is actively shopping some of these D-men. Why? Also, is Detroit's defense good now? #LGRW