I am not concerned, I don't fault him at all for wanting some structure or get traded. look at the way that organization is being run. He simply wants to keep Pierce who did a decent job. he is also not the only one singing Pierces praise, and Pierce is getting looks from other organizations as well.
a Crosby addition would strike fear in opposing QBs and OC's. he is relentless and still young, put him with Turner, Young, and Donald and that's a front 4 who would wreak havoc in opposing backfields.
I personally like Crosby, if the Rams were to trade for him, I would not be upset at all.