Wolfe - who enjoyed a breakthrough for the Reds on the first-team front in the second half of last season - has been out of action with an ankle injury since mid to late September, while Helliwell has been sidelined with a thigh issue with his last appearance coming in the 2-2 draw at Ipswich Town at the end of August.

Duff, whose side welcome Crewe Alexandra in the second round of the FA Cup on Saturday, said: "Wolfie is on the grass now and looking like he's moving a little bit closer.

"Unfortunately, Jordan has had a setback and he just felt something in a different part of his quad and he might be another five or six weeks again. That's really disappointing for him as he's been out for 11 weeks.

"It's one of those unfortunate things as he was getting closer and closer and they were both really close.

"Wolfie has not joined in with the group yet. But when you see him on the grass and some of the running he is doing, you know he cannot be too far away.

"I could not give a time-line, but Wolfie is definitely closer than Jordan now."

Alongside the duo, Will Hondermarck is out of action until the New Year after injuring his ankle in training earlier this week.

Loan striker Slobodan Tedic (ankle) is out for eight to 12 weeks after suffering the problem in the recent League One game at Shrewsbury Town.

Luke Thomas and Conor McCarthy are on the longer-term injury list after suffering serious injuries earlier this term.

Duff commented: "Will Hondermarck is eight to ten weeks and everyone else should be fine. They came through the game on Wednesday and there was nothing in the game last Saturday. It's as you were, we are still light on numbers a little bit, but the squad is the squad."

Barnsley FC's Michael Duff gives updates on Matty Wolfe and Jordan Helliwell ahead of FA Cup tie with Crewe