The former Edinburgh man has been on trial at the French club since August but the Top 14 leaders have decided against offering him a contract.
Hardie, 30, recently underwent a hernia operation and it is understood Clermont consider him not quite match fit. They also have up and coming French forward Alexandre Fischer as cover.
Franck Azema, Clermont’s sporting director, was quoting as saying that Hardie “is able to train but it is difficult to see him playing in sequence of matches”.
Hardie posted a message on Twitter, thanking Clermont. “Had a awesome couple months at Clermont, want to thank the boys, medical staff, S&C [strength and conditioning] and the management,” he wrote. “Didn’t go to plan but I’ve come out of those months fighting fit. All the best to Clermont for the rest of season.”
Stuart Hogg, meanwhile, faces a race against time to be fit for the November internationals. The Glasgow full-back is expected to undergo surgery on the ankle injury which saw him fly back early from the Warriors’ mini-tour of South Africa.
Scotland kick off their autumn series against Wales in Cardiff on 3 November.