Bischoff damaged knee ligaments and was forced off at half time against Burnley - he was replaced by club captain Lee Bullen at the break.
He is still eligible to play for Wednesday and the club are in discussions with Manchester City about keeping the Danish defender at Hillsborough if his injury is only a minor one.
If he does end up returning to Eastlands, Paul Sturrock could call on Guinea international Diallo, who has been out since the Coventry City away game in February, with the Owls boss calling the decision 'a leap of faith'.