Jack Wighton will not be allowed to return this season unless Canberra make an unlikely charge to the finals after the NRL rejected his appeal over a 10-match ban for his nightclub assault earlier this season.

The NRL on Friday announced the proposed penalty previously imposed on Canberra fullback Jack Wighton for his involvement in a pre-season incident would stand.

Wighton was suspended for 10 weeks and fined $30,000 after pleading guilty in the ACT Magistrates Court to five counts of assault and one of public urination.

He responded to the breach notice and sought a reduction in the penalty.

An NRL spokesman said that, after considering the response, the NRL had determined that the original proposed penalty should stand.