Marvin Elliott, Evander Sno, Steve Collis, Brian Wilson, Jamie McCombe and Jamie McAllister are all struggling with fitness problems.
On the search for new signings, Johnson told the club's official website: "That's not something I've brought up, it's more me giving honest answers to [press] questions.
"We're always looking at what's available, and to be honest again we're already looking at players for the end of the season and possible signings ahead of the next campaign."
Source: Team Talk
Source: Team Talk