Curtis McDonald could return to the Rovers defence but Steve Davies, Mike Fowler and Lee Ayres are all still recovering from surgery.
Forest Green manager Dave Hockaday told BBC Gloucestershire:
"If anyone thinks it'll be a cakewalk until the end of the season they're in cuckoo land. It'll be a battle, a scrap, a war - every game. We look at every game as a cup final. If we're up for every game we're good enough to stay up.
"We didn't want to lose Andy Mangan, but he's left for professional and possibly more personal reasons. Isiah Rankin has come in and done well.
"If we are able to get another striker in then great. We're tight on finances and numbers and if we can't do it, then I get on with it and I'm confident in the group that I've got."
Source: BBC Sport
Source: BBC Sport