Marown Commissioners are appealing to the public after a large pile of grit and leaves was dumped on the cycle track by the football field.
They're asking anyone who might be able to identify the culprit to get in touch with the local authority.
The Memorial Playing Fields committee adds members put in a lot of their own time to maintain them, and it's not fair to expect them to deal with such incidents.
It happened on the evening of Tuesday, October 14.
Repairs on Peel Power Station to get underway
Manx Care doctor survey to be discussed by Tynwald
Weather warning for snow tonight
MHK queries safety at primary school in Ballabeg
Gales put two ferry sailings at risk tonight
Should the Island throw a birthday party for Barry Gibb?
Warning issued over icy roads
High ground could see 4 inches of snow on Saturday night