Here is a solution that I think will work. Teams A to D are the ones that play each other early:
(a b) (c d) (F I) (E H) (G J)
(E G) (I J) (a c) (b d) (F H)
(b c) (F J) (E I) (G H) (a d)
(D G) (A H) (B J) (E F) (C I)
(E J) (C G) (D H) (B I) (A F)
(H I) (B F) (D J) (A G) (C E)
(D F) (G I) (C H) (A J) (B E)
(H J) (A E) (B G) (C F) (D I)
(A I) (D E) (F G) (C J) (B H)
I have used lower case to identify the 6 early games for a to d. There should be column balance, so teams should appear once or twice in each column.
