The Owls are currently 16th in the Championship and needed a replay to find their way past League One high-flyers Luton Town in the previous round.
Nevertheless, they are available at 21/2 (11.50) with SportPesa to knock out the cup holders with a first win at this ground since 1993.
Maurizio Sarri's men booked their place in the Carabao Cup final with a penalty shootout victory over Tottenham on Thursday, and are 20/87 (1.23) favourites to keep themselves en route to more cup success with a victory here.
Three of the guests' last four FA Cup ties have gone to a replay, and you can get odds of 5/1 (6.00) on them grinding out an impressive draw in this one.
Gonzalo Higuain could be set to make his debut after joining on loan from Juventus on Wednesday, although Ruben Loftus-Cheek is still ruled out with a back injury.
Fernando Forestieri is in contention to return following injury but Matt Penney faces a spell on the sidelines after undergoing shoulder surgery.
While fans will hope that Higuain's arrival will help to inject their team with some much-needed cutting edge, they can already feel confident of their defence keeping things tight at the back.
Having conceded just three times in 10 matches on home turf, the Blues are unlikely to have any difficulty in keeping at bay a visiting attack that has scored only 15 goals in the last 18 fixtures.
All in all, odds of 10/11 (1.91) look like solid value on Chelsea easing to victory without conceding against a goal-shy Wednesday team.