Jarrod Evans is to leave Cardiff at the end of the 2022-23 season.
Harlequins have been strongly linked with a move for the Wales fly-half as cover for England’s Marcus Smith.
Cardiff head coach Dai Young said the club was unable to match an offer for the 26-year-old due to the drastic budget cuts facing all four Welsh regions.
He added that the club also expects to lose injured pair Willis Halaholo and Dmitri Arhip.
Evans, who emerged through the club ranks, has played more than 120 times for Cardiff and totalled more than 750 points for his home region.
Young said: “I can’t tell you where Jarrod is going, that’s his business, but I can tell you we can’t put a competitive offer on the table anywhere near the offers he’s had.
“So we’re pretty much feeling that he is leaving unfortunately which is really sad, when you think that kid’s been here since he was 14.”
Evans won the last of his eight caps against Argentina in November 2021 and will be ineligible for Wales under the new 25-cap selection rule.
Young added: “I think in his heart of hearts he doesn’t want to leave, but at the end of the day he’s got to do what he thinks is the right thing for his family and I support him personally in that decision.”
Rhys Priestland has already confirmed he will depart the Arms Park this summer, leaving Cardiff without a recognised outside-half for 2023-24.
“We haven’t got any [outside-halves] to be honest,” he said.
“We’re in the market place looking for replacements, as we are for a number of positions.”
The news came in the week regional coaches said they expected to lose several star players.
Cardiff have said they are struggling to make competitive offers for several leading players as they prepare for a £2m budget cut next season.
Asked about Wales centre Halaholo and Moldovan prop Arhip, who are both facing lengthy lay-offs with Achilles injuries, Young added: “We are there to look after rehab for [them], but where they are going next year I don’t know.
“I don’t know if they’ll be our players next year. They knew the decision the club had made before their injuries.
“If we haven’t got money to have competitive offers for Jarrod, why would we have the money for Willis and Dmitiri?”