McCammon, who scored twice in six games last season whilst on loan from Sheffield FC, has been handed the number 37 squad shirt and will go straight into the squad for Saturday's Blue Square Bet Premier match at Newport County AFC.
The 34-year-old started his career at Cambridge United before joining Charlton Athletic, then in the Premier League, in March 1999.
He signed for Brentford for a six-figure sum during the summer of 2000 and went on to spend almost three seasons at Griffin Park before linking up with Millwall towards the end of the 2002/03 campaign.
Appearing as a substitute for Millwall in the 2004 FA Cup Final, McCammon then moved to Brighton & Hove Albion following a loan spell with the Seagulls but with first team opportunities limited, he linked up with Bristol City on loan before moving north to Doncaster Rovers.
The first player to score at Rovers' Keepmoat Stadium, McCammon won the first of five caps for Barbados in 2006 and had the honour of netting a hat-trick against Anguilla in a 7-1 Caribbean Cup Qualifying match.
He spent two seasons with Doncaster, helping them to promotion to The Championship via the play-offs before playing over 50 times for Gillingham.
Leaving the Gills in the summer of 2011, McCammon played a handful of games for Braintree Town early last season and with the Essex club failing to cancel his registration, he signed forms with Sheffield FC early in March 2012 who immediately loaned him to us until the end of the campaign.