Fletcher played 90 minutes on Tuesday night, in a reserve-team friendly at Stalybridge Celtic.
The Scotland skipper had been out of action since November last year due to a chronic inflammatory bowel condition.
It had been feared that Fletcher would never play again.
"Darren's training well and played in the reserves on Tuesday night. The next step is when we can involve him in a game in the first team," said Ferguson.
"He's in the squad tomorrow, simply because I think it will give him a boost. It's a chance to progress. At this moment in time everything's going fine for him.
"We understand the condition he has to deal with [ulcerative collitis]. That can change but hopefully he's managed to conquer it in terms of his diet and how he handles it. Things are going well at the moment."