Bednarek, 28, sustained a knee injury while playing for Poland against Portugal last month, and has missed games against Liverpool and Brighton.
Martin is also optimistic that forward Paul Onuachu will be involved against Enzo Maresca's side after missing Friday's trip to Brighton.
The Nigerian international did not travel to Amex Stadium to avoid exacerbating his issue, despite Martin's temptation to bring him.
Previewing the game, Martin said: "We're hopeful that Paul will be involved on Wednesday, which will be good for us.
"Apart from that, Janny B will be back in the squad as well, hopefully, all being well."
Saints will be without Flynn Downes, Taylor Harwood-Bellis and Tyler Dibling after the trio picked up a one-game ban for accumulating five yellow cards.
Saints boss Russell Martin and Taylor Harwood-BellisSaints boss Russell Martin and Taylor Harwood-Bellis (Image: Gareth Fuller/PA) Loanee Lesley Ugochukwu is also unavailable due to Saints facing his parent club Chelsea.
On adapting his team with those absences, Martin added: "We have to accept we're missing some key players but we also have a lot of trust in the players we have.
"We have a lot of trust in the players we have available. It's quite exciting for a couple to have an opportunity.
"It's quite exciting trying to work out the best way to accommodate for the suspensions and injuries.
"In the same way we did when Rambo and Janny B (got injured). We knew they were going to come out.
"You just try and work it out, don't you? Adapt and flex. We have big trust in the players that are coming in.
"We have big trust in the shape we're going to play on Wednesday and the players that are in it, because they've done it before."
Saints starlet Tyler Dibling will not face Chelsea on WednesdaySaints starlet Tyler Dibling will not face Chelsea on Wednesday (Image: Richard Crease) Asked if he regrets playing Downes, Dibling and Harwood-Bellis at the same time, risking losing all three, Martin said: "No.
"Am I kicking myself about playing three of our best players away from home against a team that went second in the Premier League? Absolutely not.
"The five booking thing, when you play in certain positions, if they're good bookings you can really accept it.
"I think a couple of them were for descent, which is annoying because it shouldn't be the case.
"We ask the team to be aggressive, to play in a certain way, to press high, to try and dominate with the ball as much as we can.
"Sometimes they're going to have to take a booking for the team. If they're good bookings, you have to accept that as part of it.
"I think the three of them being banned at the same time is probably a bit unusual. They've been three top players, but it's one of the things that's happened."