I had the same problem.
I also have Messi, Neymar, Van Persie, Muller, Robben and Rodriguez (out).
Plus 2 dutch defenders, 1 argentina defender, and argentina goalie (plus Columbia defender who it out).
I did consider taking a punt on Aguero of Argentine as he is back from injury, but felt he was a risk, or maybe Oscar of Brazil or Higuan of Argentina.
In the end I took out Neymar went for Ozil of Germany in Midfield as he does pop in with the odd goal now and again.
But to be honest it is all guesswork as none of us knows who will do well and score goals in the next two matches.