No Problem. I teach my students this technique all the time. Thread a fine needle with regular sewing thread that matches the yellow (green would work also) about 10 inches long and make a small knot. Bring the knot up from the back side, right at the edge of the small hole to the right side of the block. Work from the RIGHT SIDE to do the following. Catch two threads of each diamond right at the edge of the hole, going around the hole in a circle into each of the 8 diamonds. Bring the needle and thread out to the RIGHT SIDE of the block. Here's the magic---draw up the thread and the hole will close perfectly. Finally, poke the needle to the back of the block, knot and cut the thread. This works if holes are fairly small, but if you can stick your finger through the hole, then it needs to be redone. However, yours will close perfectly.
I always make my stars in this fashion, adding one diamond to another (1 to 8) and close the final seam to create the star. This method ALWAYS leaves a tiny hole which I close as mentioned. Perfect matching!
Rest easy, it will work.
SandyQuilter