I found the same little holes in my Tyson frozen chicken breast. Figured it was injected. Living Alaska and often see fresh salmon with little worms, only wild caught never in store. I thought I would check if anyone else has seen this. Don't freak about the Salmon worm thing. You just filet it and pick out the worms along with any bones before cooking. In Halibut also. A little extra protein won't kill you ;)
Tyson Boneless Skinless Chicken Breasts are ready to Cook, no thawing required! Each portion is broth enh anced for tenderness and individually frozen. ...."
A friend of mine mentioned that she was pretty sure that it was part of the freezing process.
On an unrelated note, this is my first time posting in this forum, love the quick responses, thanks everyone