With such a strong opponent, a defensive strategy might be the best choice for Schalke, and at any time they can take advantage of Bayern Munich's mistakes to carry out a quick counterattack. I know very well that defensive strategies have a lot of risks, because if they are pressed continuously they will tire more quickly, and when fatigue starts to get in the way, it will result in decreased concentration. And in the defensive strategy they have to be able to maintain concentration, maybe that will be an additional job for a coach.
Meanwhile, clubs that play offensively will usually leave gaps in the defense, and Schalke can take advantage of that, and at times like that they are required to play effectively when they have opportunities.
surely the match between bayern vs schalke will be very tight, bayern is struggling to keep away from dortmund while schalke is fighting to keep away from the relegation zone, but i predict bayern will win easily in this match, it will be difficult for schalke to withstand attacks from bayern.