The 24-year-old left-back featured in several pre-season games for boss Chris Kinnear’s side after returning to England following a spell playing for Georgian top-flight team FC Zugdidi.
Deen-Conteh, who has three caps for his native Sierra Leone, came up through the ranks at Chelsea after joining the club when he was 13.
He won the FA Youth Cup during his time at Stamford Bridge and was also named in then manager Roberto Di Matteo’s Champions League-winning squad in 2012.
After being released by Chelsea in 2014, he spent a year with Greek Superleague side FC Ergotelis before he returned to England to join Port Vale.
He left Vale Park for Moldovan side Zaria Balti in January 2016 before the move to FC Zugdidi.