Guess it depends on how far from the action you are, and what type of shots you are after.
My first choice would be a zoom for covering the action at a variety of focal lengths.
Good Luck!
I'm with Dave, a zoom is your best option but you'll need to stop it down to get a deeper depth of field unless you're really adept at manual focus - why not use a lumix lens rather than fully manual?
The FD 85mm f1.8 is my favorite lens from my FD collection, but remember its became 170mm on the m4/3 and the shake will be very pronounced, for live action i totally recommend you to use the 14-140mm, OIS, AF focus, good in light or exteriors, versatile zoom range.
Can't afford the 100-300 unfortunately. I have an fd 80-200 f3.9, would that work? I'd like to shoot in slow motion and get relatively close to the players.