Mix cream cheese with about 2 teaspoonfuls of reserved mushroom juice using a hand mixer. Season with garlic powder, salt and pepper to taste. Add mushroom pieces and chicken and mix well. Add a little more mushroom juice if too stiff.
Use 2 crescent rolls for each pocket. Roll the 2 crescent rolls to seal seam. Place 1/8 of mixture in middle of crescent rolls. Fold and press ends together to seal. Place on nonstick cookie sheet. Repeat with remainder of ingredients. (will make 8 pockets) Cook at 375 degrees for 20 minutes or until golden brown.