Place cabbage in microwave-safe bowl. Add 2 tablespoons water.
Cover. Place in microwave and heat on high 5 minutes.
Remove from oven.
Remove 8 leaves and trim out thick stems. Set aside.
In large bowl, combine sausage, rice, green pepper, onion and 1/4 teaspoon chili powder. Mix until blended.
Place 1/2 cup sausage mixture on each cabbage leaf and roll up.
Place rolls in slow cooker.
In another bowl, combine tomatoes, tomato sauce and 1/4 teaspoon chili powder. Pour mixture over cabbage rolls.
Cover and cook on low for 6 to 7 hours or until sausage is cooked.