MIDFIELDER Conor Henderson has signed for the Mariners on a deal until the end of the season.
The 24-year-old, who has just spent a month with the Mariners on loan, was released by his parent club Crawley last week.
He started out at Premiership side Arsenal, making one appearance for the Gunners back in 2011, during the 5-0 victory at home to Leyton Orient in the FA Cup.
He enjoyed a brief spell at Coventry a year later, before making a permanent switch to Hull City in 2013.
Henderson only featured once for the Tigers, but a successful month at Stevenage earned him a move to Crawley in 2014.
Born in Ireland, the midfielder has made 20 league appearances for Crawley, scoring twice.