I was hoping someone else would know more than me but as you've had no other replies I'll add what I do know. I was phoned by a gentleman who lives near there last week who had found my contact details after googling for the recreation ground.
He said that there is a lot of work to be done on Strines Road (12 months or more I think) and part of the recreation ground is to be used as a contractor's compound. He was under the impression that this kind of activity had been stopped in the past because the covenant when the Rec was given to the people of Marple in 1910 by Walter Hodgkinson forbids this kind of use.
I was able to give him a partial copy of the covenant for Memorial Park, which is probably similar, but I haven't seen the one for the Rec and suggested that he get in touch with Marple Local History Society. If the compound disappears overnight you will know that he's been successful in getting it stopped.