Schalke play a standard 4-2-3-1 . Two solid center-backs who like getting forward as well. Think Luiz, but a little less erratic. Two wing backs on opposite sides who love charging forward and providing width.
In the middle we have the pivot, both of them either defend or attack. There is no vice-versa role as it happens in Chelsea for Schalke. They defend together, or attack together. It helps Schalke in a way, which we shall see later.
The front three function like interiores , as they drift a lot into the center. The striker has the ability to drift, which gives theinteriores and the #10 an opportunity to move forward and function as a #9. The attacking midfielder has also been noted to play as a second striker, especially when the #9 pulls back and links up with the midfield.

Now we have their transition to defense. The wing-backs now squeeze themselves inside, as the wingers come back to ensure that the whole structure doesn’t become too narrow. Two blocks of four is what Schalke used against Bayern. Yet they suffered a heavy defeat due to not taking their chances by exploiting the flanks.
The middle three press together at the ball, and have a peculiar relationship. Each of them have hybrid profiles in a sense that they can take up each other’s position while pressing. This gives them the freedom of movement with security in mind that the other two are covering. One out of the three never presses. He stays back and provide protection to the back four, and covers holes opened up by the pressing midfielders.
Schalke always always always mark zonally. It’s like they are allergic to man marking. Even their pressing is zonal rather than charging right at the player.
If the ball is won, Schalke charge down the wings. This is a strategy used by almost every team that likes using two blocks of four during defensive transitions. The wingers or interiores are the main outlets when the ball is won back, the striker being secondary. All of them push up, including the attacking midfielder and the wing-backs in a bid to create a clear cut chance.
Now when it comes to transitioning to attack, Schalke aren’t afraid in committing men forward. The wing-backs play akin to Alaba and Lahm of Bayern. The wingers on paper show the true qualities of interiores by shifting in ward. This cramps up and causes congestion in the center of the final third.
A quick switch of play to the flanks and the opposition have problems to deal with. Schalke can be threatening by frequently applying this strategy. If the play is switched back and forth too quickly, opponents who don’t have high concentration levels , pay the price.
Considering that Schalke don’t exactly play full-backs, they are highly vulnerable on the flanks. To counter this, the pivot restrict their movements forward. They opt to stay back and defend ahead of the center-backs 75% of the time. If the ball is lost, most team’s play down the flanks to exploit that space. One of the pivot players intelligently closes them down, while the attacking midfielder joins up with the other pivot player in the center.
The wingers meanwhile retreat back as well, giving Schalke further options to recover the ball back, or hinder the attacking transition of their opponents.
This helps Schalke slowly regain its shape as they wait to counter the next time they get the ball back. One thing to be noted is that Schalke will enter the game without any fear. The plethora of players at their disposal could give Chelsea a run for their money. Chelsea will be forced into working really hard if they want to get anything out of the game. Not to forget that concentration and work-rate must be high. Schalke are going to make us run all night if they have to.
I expect Azpilicueta to start the game. He seems to be much more clinical down the flanks than Ivanovic has been this season. Moreover Torres is also likely to start. One thing the Spaniard has to do is harass the German back-line. Only then will spaces open for Chelsea’s wide players to directly penetrate. I don’t see Eto’o having the capability of doing something like that. We don’t want too much drifting towards the flanks.
There’s a slight possibility of either Mikel starting at the Veltins-Arena. Chelsea need a pure defensive midfielder to stay back during attacking transitions as this would limit the amount of damage Schalke could cause.