Wallace missed both legs of the original first-round tie with a hamstring injury but his manager, Howard Wilkinson, is hoping the former Southampton player will be available against the German champions.
'I haven't ruled him out of my plans yet. We will have to wait and see,' Wilkinson, whose team flies out to Spain this afternoon, said.
'The lads are very keen to make sure they get into the next round and meet Rangers on merit. Certainly they fancy their chances.'
The Germans, meanwhile, are already in Barcelona preparing for the replay, which was ordered by Uefa after Stuttgart fielded four foreign players, rather than the permitted three, in the second leg at Elland Road last week. Stuttgart won the first match 3-0 and despite a 4-1 defeat in Leeds would have gone through on away goals but for their accidental indiscretion.
Tomorrow's replay will be a one-off match which will be decided, if necessary, on penalties after extra time. The Nou Camp, normally a cauldron of Catalan passion, is offering cut-price tickets - pounds 9, pounds 15 and pounds 21 - in an attempt to drum up interest in the match, which was arranged at 72 hours' notice.
Leeds are expecting as many as 1,000 fans to make the trip to Spain. The club's secretary, Nigel Pleasants, said: 'We have chartered two planes and fans were queuing up today to book places on a convoy of coaches that will be leaving on Thursday evening.'Reuse content