Here's a possible schedule:
(A B) (---) (---)
(C D) (E G) (F H)
(B C) (A G) (D F)
(A H) (C E) (B G)
(F G) (E H) (A D)
(B H) (A F) (C G)
(A E) (B D) (C H)
(D G) (C F) (B E)
(E F) (D H) (A C)
(G H) (B F) (D E)
As there are 28 games to play, a number which is not divisible by 3, there must be a short round with just one game.
