The Bundesliga side beat champions Borussia Dortmund in the weekend and look like genuine title challengers this season. With players like Klaas Jan-Huntelaar, Lewis Holtby and Ibrahim Afellay in their ranks, there is no reason why they cannot sustain their good form should they keep their main players fit for most of the season. They will provide a serious threat to the Arsenal defense, who will have to be at their best to not let Schalke have many opportunities. Huntelaar is a player who is a perfect "fox-in-the-box" sort of striker and is not likely to pass up good opportunities to score and he has got some good players like Afellay, Farfan and Holtby who will support him well.
For Arsenal, the good news is that Laurent Koscielny is fit enough to come back to the squad but the question is whether or not he will be in the starting line-up. Per Mertesacker has done very well this season and if fit, he is most likely to start. Thomas Vermaelen does make mistakes at times and though he is a very good player, it has to be said that the decision to make him the captain of this Arsenal side is questionable considering that Koscielny could be considered a serious contender for his place in the starting line-up. The French international was arguably Arsenal's best defender in the last season and though he had a poor game against Chelsea, he deserves another chance to have a decent run in the side. Mikel Arteta would have been a more appropriate choice to be named as captain considering that he has the leadership skills and is also extremely consistent on the pitch.
Wenger has made his choice though and will have to stick with Vermaelen and Mertesacker as his first choice defensive pair because Koscielny and Vermaelen as a partnership does not look to be too stable. With Huntelaar leading the line, he will cause plenty of problems for Arsenal and Mertesacker and Vermaelen will have a tough task to keep him quiet. With Gibbs not likely to feature against Schalke due to injury, Andre Santos is likely to be entrusted with the duty of stopping the supply of crosses from the right flank. Carl Jenkinson has been very impressive this season and will start again against Schalke but with him more or less a regular member of the side now, he has to also improve on his attacking duties and deliver more accurate crosses from the right for the Gunners. With Olivier Giroud leading the line for the Gunners, Jenkinson's crosses could be important in adding another dimension to their play.
In midfield, Aaron Ramsey could make way for Francis Coquelin, who deserves a chance considering that he has played well whenever given the opportunity to do so. The Welsh international had a woeful game against Norwich and needs to be benched for maybe a couple of matches unless he improves on his standard of performance. Arteta can be very influential further up the pitch as well considering that he and Cazorla do share an excellent understanding and the Spaniards have the capability of breaking down defenses with their vision and creativity. Jack Wilshere is not likely to make the squad having played the entire U-21 game against Everton on Monday but is likely to be on the bench for the game against QPR. His return to fitness is a timely boost for the Gunners, who have got a number of first team players out through injury.
With both Theo Walcott and Alex Oxlade-Chamberlain out for the game against Schalke, there are not many options left for Arsene Wenger other than to continue playing Gervinho out wide with Giroud leading the line. Gervinho does not look at his best on the right wing and did have a very poor game against Norwich City. Lukas Podolski will continue to start on the left flank and the German international who will be facing familiar opposition will be looking to make an impact. With Arsenal no longer having Robin van Persie to rely on for the goals, all the attacking players will have to step up and perform at their best if they want to seriously challenge for trophies this season.
It is a difficult task for the Gunners to defeat Schalke but a win will give them huge impetus after their defeat and importantly would put them in pole position to qualify as the Group toppers. It will allow them breathing space at the top of the table and will be a huge relief for Arsenal. It will not be a easy task but Wenger will be looking for a positive reaction from the defeat against Norwich City. Arsenal's mental strength will be put to the test on Wednesday against a tough team in front of a crowd who will be anxious right from the start. It is up to the team to show their quality and prove that the defeat against Norwich was just a one-off game. With plenty of important games coming in quickly from now till the end of the year, it is of vital importance that Arsenal beat Schalke and establish their position as the Group B leaders in the Champions League.