The former blaes playing fields in Victoria Park are being marketed in an online advert.
Glasgow City Council said last year it was considering renting out park facilities in a bid to generate funds.
Bosses contracted property consultants Ryden to undertake a feasibility study on Victoria Park.
In a report Ryden listed potential uses for the north west area of the park, including a retail development, a pub or restaurant, a garden centre, an open-air market or children's soft play.
Park-goers are worried they will end up with a large commercial develop-ment they have no say in.
Cathie Russell, 59, was one of around 200 people to attend a public meeting earlier this year where the council said they would do some market testing.
She said: "The council said they would consult on it - but there's a big difference with doing that and then advertising it.
"I don't want to see any building on it, unless it was a small one for community use.
"Once it's being used for commercial use it can be turned into anything."
Ms Russell said she believed most people wanted to make the use of the open green space.
Surveys conducted by Anniesland MSP Bill Kidd last year found 69% in favour of an orchard, nearly 60% against 3G pitches and more than 60% against a garden centre.
Local resident Brian Peters said: "I lived my first 18 years right across the road in Victoria Park corner and would hate to see part of my former playground turned into a pub or anything similar.
"Sure, it's been neglected but that should be no excuse to dump it. This is the Dear Green Place and I don't want to lose an inch of that."
Councillor Kenny Mclean, Partick West SNP councillor, said: "I am concerned that the way this is being done will mean it could be opened up for commercial use. I will be seeking assurances from the council."
Councillor Feargal Dalton said: "I can understand why there are concerns and I don't want to see any plans that go against what the community wants."
A council spokesman said: "Local elected members, local community councils and Friends of Victoria Park have been kept abreast of any developments and are all aware that Ryden recently commenced this exercise and are due to report in early September.
"We have always been clear that, prior to reaching any conclusions, the results of this exercise will be fully shared with, and discussed with, local elected members, community councils, and any interested parties."