Cornish Pirates chairman Paul Durkin says the survival of the Championship rugby side, and Truro City Football Club, is his priority after plans for a new stadium were put on hold.
Cornwall Council has not put the Stadium for Cornwall project forward for government levelling-up funding.
A smaller project could replace the planned 10,000 capacity arena in Truro.
"We're going to press ahead to try and make sure something happens," Durkin told BBC Radio Cornwall.
The Pirates own Southern Premier League South side Truro City and the teams were to share the new stadium.
Truro are playing their home games at Plymouth Parkway's Bolitho Park ground, 55 miles away from the city, after their Treyew Road ground was sold to developers last year.
A community interest company (CIC) had been set up to fund the new ground and had applied for £14m, to add to the £11m already raised for the build.
"Our priority is to ensure the survival of both Truro City and the Cornish Pirates," added Durkin.
"[Truro City] are the most urgent. We have a groundsharing deal which lasted for two years and one year is already up.
"The understanding from the council at the time was that a smaller stadium could be built in the period required, as there is also Section 106 funding available to Truro City from the sale of Treyew Road - that was to go towards part of the funding of the stadium.
"Our job now is to try and find private funding, and funding from other organisations, to get a smaller stadium up there and running to enable Truro City to come back as soon as possible."
Durkin critical of Cornwall Council
The Cornish Pirates finished third in the Championship last season but are not in a position to apply for promotion as their stadium at the Mennaye Field in Penzance does not meet the Premiership's minimum capacity criteria of 10,001.
Any smaller stadium that is built would have to be expandable, should funding be found to allow the Pirates to play in the top flight.
Durkin was critical of Cornwall Council's handling of the situation - the stadium first got planning permission in July 2015 and Truro City agreed to share the ground in April 2017 after having plans for their own separate venue approved at the same time.
"We had been basically promised, in fact the council made a public statement to say that they supported the stadium project as part of levelling up and asked the CIC to draft the bid with their support.
"While doing that they told us it was withdrawn."
He added: "There are people's livelihoods that are risk, these are professional sportsmen, it's the coaches, it's everybody there.
"It's also the aspirations of the Cornish people themselves - I don't know if you've looked at what the reaction has been on social media, but it hasn't been in favour of the council."
In a statement, Cornwall Council said: "Due to a change in the levelling up fund [LUF] criteria Cornwall Council has taken the decision not to submit a bid for the Stadium for Cornwall project on this occasion.
"We had understood that submissions to the 'culture' strand of LUF were additional to the six Parliamentary constituency bids we are able to put forward under the rules. However, this is not the case and we have taken the decision to focus on those constituency bids at this time.
"We would like to thank the stadium partners for the work they have done and will continue to work with them to identify appropriate funding opportunities in the future."