Here goes: I need more information to answer your question .... this is the kind of thing you cannot decide unless you know who you are working with.
1st, since there are 4 matches I assume you count courts and the champs are determined by how many courts you win over the entire season. Is this so?
2nd, for this particular match do you expect a tough team, a weak team or do you have no idea?
3rd, is the title soley determined by the regular season? Or do half of the teams qualify for some sort of season ending playoff? How did this squad do last year if applicable?
4th, how well do you know your players? Often times just putting the two best guys together does not give you the best team. Perhaps there are advantages to particular partnerships?
5th, how many total folks on the team? Will you just be working with a skeleton crew or will these guys likely never be on the courts at the same time again?
I would chose the the combinations that maximize your needs for each of these questions.
"You should be playing linebacker, not singles."