Barnsley: Reds sweating on fitness of Kieffer Moore and Cauley Woodrow
Top-scorer Moore missed last week's win over Luton with an ankle problem while Woodrow, a summer signing from Fulham, has yet to make his debut due to a muscle injury.
But both players are closing in on full fitnessÂ and could be back in the Reds' squad at the Valley.
'We hope that they can train Friday,' Winkler said.Â Â
'They are doing everything with our sports scientist and the physio, today and the last week, so hopefully but we are not sure.
'They are different kind of injuries. Kieffer has a swollen ankle so we have to see if it is no risk for him to play and how his pain is.
'Different to Cauley, he has an injury in the muscle. He has to have a speed like 95 per cent when he trains with our sports scientist and he was at 90 yesterday. He is close.'
The availability of Moore and Woodrow would leave Tykes boss Daniel Stendel with a selection headache.
Stendel was also without the services ofÂ WalesÂ goalkeeper Adam Davies andÂ AustraliaÂ midfielder Kenny Dougall due to international commitments againstÂ Luton.
But Barnsley showed they have plenty of depth in their squad, beatingÂ the HattersÂ 3-2 in front of the Sky Sports cameras at Oakwell to move into third place in the League One table.
'A change (in formation) I don't think so. Our most likely formation is 4-4-2,' Winkler said.
'They are two strikers, but different players. If both players are available on Saturday, inÂ GermanyÂ we would say we have a good bench!
'It is difficult, but this is how you hope to have it as a coach. One way it's difficult, the other way you like it.
'Everybody has to know that we can only be successful as a team. If you have an impact as a substitute or they play from the beginning.'
Mid-table Charlton have had a dip in form recently, failing to win any of their last three league matches, but Winkler knows what to expect from the Addicks.
'They are a pretty good team,' the German added. 'In the previous season they almost got to the Championship, but they didn't.
'They have a very ambitious coach, a manager who played in higher leagues, and I think they are very similar toÂ Luton.
'They have a clear formation, a clear idea of football, and a big stadium.
'It is like Bradford, almost bigger, but we will have lots of supporters from Barnsley, maybe 2,000 or 1,500 toÂ LondonÂ which is amazing, unbelievable.
'I think we will show a very good performance, but we need this performance to take the three points from Charlton.'