Owen and Karl Oyston sued fan David Ragozzino for Â£150,000 over a post on website Another View From the Tower.
The 32-year-old said he had "limited financial means" and feared what would happen should the Oystons win the case.
The judge at Manchester Civil Justice Centre gave him 21 days to respond to the claim.
The application to default hearing was brought by the Oystons on the grounds Mr Ragozzino had failed to file a defence in time to their action.
He was supported at the court by dozens of Blackpool fans, who carried banners that criticised the Oystons' running of the club.
On Friday, fellow fan Stephen Sharpe apologised to the Oystons over his online comments, withdrawing his posts after accepting they were "false, defamatory and, in some cases, threatening".
On Saturday, about 1,000 fans staged a demonstration before the club's home game with Brighton, calling for the Oystons to relinquish control of the club.
A Blackpool football fan who is accused of libelling the club's owners on the internet has told a court he has "never written anything defamatory".