YES you can make a 23" finished block from a 'regular' cut!
Use NINE 8" square blocks to make your 9-patch.
You will need about 1/2 yard - which will have some leftover - if you use only one fabric.
Or you could use a "Layer Cake" set (usually 10" x 10" squares), recut for your 8" square and have ONE 2" x 8" leftover strip from each 10" block.
Jan in VA