Rather than do that, I would make a class for your Sudoku tiles so you can keep all the relevant data together. One of the fields and properties will be the integer value of the tile, you can use that to ensure you don't use the same one twice. This integer value can also tell that class what its texture name is (i.e. if the value for that class is 3, then it's texture would be located at "Textures\Tiles\3". Then you can make a 9x9 array of these tiles and fill them in as appropriate.
