The 24-year-old, sidelined for the last eight matches due to an ankle ligament injury, was poised to return earlier but missed out last week through illness.
"Josh Walker is back training and we're delighted with that," manager Brian Laws told the club's official website.
"He'd been ill, but he's back now and is fighting for a spot in the side. He strengthens us at a time when the squad isn't the biggest."
Laws has also received a boost with regards to the fitness of another midfielder, Damien Mozika, and defender Christian Ribeiro, who have both been out with hamstring injuries sustained earlier this month.
"Damien and Christian are about a couple of weeks away and are progressing really well," Laws added.
"It would be nice to get them back over this next couple of weeks because we have a lot of games and our resources are stretched to the maximum."