The 'Grow 4 Joe' campaign has been set up in aid of Tranmere Rovers' Joe Thompson, who was diagnosed with Nodular Sclerosing Hodgkins Lymphoma - a form of throat cancer - back in October.
The general idea for the fundraising project is to see footballers, staff members and fans throughout the leagues either grow their hair or facial hair to help raise money for charity and to show support to Joe during his treatment for the disease.
To help support the sponsored 'Grow 4 Joe' challenge, Darby and Bennett have vowed to grow their hair until at least the end of the current season.
Both Darby and Bennett know Thompson through their time in football.
The pair can be seen in the picture at the bottom of this article holding a special 'Grow 4 Joe' Bradford City shirt, which has been signed by all of Phil Parkinson's squad and will be auctioned off.
All the money raised from the challenge will go to Leukaemia and Lymphoma Research.
The original idea for the 'Grow 4 Joe' fundraising campaign came back in January from Thompson's Tranmere team-mate Max Power, who is also joining in with the sponsored hair grow.
Other players involved include Peterborough United's Nicky Ajose, Rotherham United's Nicky Adams, Blackpool's Nathan Eccleston and Reading quartet Adam Le Fondre, Hope Akpan, Nick Blackman and Garath McCleary.
Donations can be made at www.justgiving.com/grow4joe .