I think the last game is the one the fixtures computer and compilers have left over with which is completely random after all the parameters are more or less met to accommodate the 92 clubs over the course of the season.
The final game of the season and for Boro it might be crucial to them , an Albion win or even a draw could see their chance of automatic promotion slip away and end up with the lottery of the play offs. Perfect for Sky to televise.