Thomas Tuchel's Key Tactical Decisions Ahead of Bundesliga Opener vs. Mainz 05

Finally, the Bundesliga is back in action on the weekend.

Although Euro 2016 and even the Olympic football tournament, where fans of Borussia Dortmund watched two of their players win a silver medal with Germany, broke the monotony of Bundesliga downtime, it's about time Germany's top flight kicks off.

For the Black and Yellows, it's going to be an interesting campaign. After losing three key players in Mats Hummels, Ilkay Gundogan and Henrikh Mkhitaryan and replacing them with no fewer than eight new signings, ranging from promising teenagers to FIFA World Cup-winners, anything and everything seems possible this season.

It's the second year at the helm for Dortmund boss Thomas Tuchel, whose impressive first campaign in charge is arguably the biggest cause for optimism at the dawn of the 2016/17 season. Under the 42-year-old, the club rebounded from a wholeheartedly disappointing last 12 months of the glorious Jurgen Klopp era, finishing the league with the second-highest points total in club history.

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The Ruhr side kick off their new campaign against Tuchel's former club, incidentally, Mainz 05.

The Zerofivers came in sixth last season, a huge accomplishment given the club's comparatively negligible financial firepower. It's likely going to be a more difficult season this time around for the club from Rhineland-Palatinate, with bigger outfits that finished below them investing heavily in their squads.

The return to European football may also take a toll, as many smaller Bundesliga clubs have experienced in the last few years.

On the transfer market, Mainz were quite busy themselves, signing seven players despite losing only two regular starters. Of course, those two were the No. 1 goalkeeper in Loris Karius, who joined up with Klopp at Liverpool, and team captain Julian Baumgartlinger, who left for Bayer Leverkusen.

Without two of their most important players, Mainz seem yet to find their feet, as evidenced by their narrow escape in the DFB-Pokal. Against fourth-division side SpVgg Unterhaching, the Zerofivers were ahead 3-1 with two minutes of regulation to play, only to concede twice in the dying moments.

They advanced after penalties, with head coach Martin Schmidt choosing to look at the positives: "We managed to get a result in Unterhaching after the narrow win on penalties which I wouldn’t swap for a 5-0 win," he said, per the club's official website. "We will start the new season fully focused and our experiences from the match could be very useful for us in the coming weeks."

Dortmund beat Mainz 2-0 in both meetings last season, but Tuchel's former team is a strong opponent for the curtain raiser.

Here, Bleacher Report takes a look at two key questions the boss of the Black and Yellows needs to find answers for ahead of the match.

How to Deal With Mainz's Pressing

In many ways, Mainz are the quintessential Bundesliga team, tactically speaking. Schmidt almost always plays a 4-2-3-1 formation with two central midfielders who are largely responsible for build-up play and defensive stability, while quick wingers track runs from full-backs defensively.

The central attacking midfielder—usually Yunus Malli, who almost joined Dortmund in the winter transfer window, as the Zerofivers announced on their website—acts like a second striker when the opponent has the ball, and both he and the lone striker apply pressure on the centre-backs in the early build-up phase.

The idea is to force inaccurate long balls that their own back line can scoop up, while the entire team is actively trying to win rebounds.

Mainz were quite successful with their pressing strategy against Dortmund last season, especially in the first meeting of the campaign at home. As the graphic below shows, the Black and Yellows' passing was wildly inaccurate by their own lofty standards (the blue line shows the stats of the first half of the season):

The Black and Yellows were deserved winners of the game and made life harder on themselves than it should've been, with Shinji Kagawa and Pierre-Emerick Aubameyang missing a number of golden opportunities and Marco Reus missing a penalty, but it was still a strong performance from underdogs Mainz.

Tuchel lauded his team's resiliency in his postgame press conference: "What delights me the most is that we accepted things as they were and didn't show any uneasiness with the way the match was going."

Dortmund can expect their opponents on Saturday to again try to turn the game into a slugfest. Despite losing their aggressive leader in Baumgartlinger, Schmidt's side showed in pre-season that they're going to continue to be a nuisance with early, high-intensity pressure.

The graphic below from a pre-season match against UEFA Europa League winners Sevilla shows that relentless attitude high up the pitch:

WyScout

The Black and Yellows struggled with pressure in many instances last season and suffered a defeat against Athletic Bilbao in pre-season because of the Basques' winning the ball thanks to their repeated pressing, as this writer detailed in an earlier piece.

Dortmund didn't experience the same problems in either of the first two competitive matches of the season, but neither the DFL-Supercup against Bayern Munich nor the easy first-round cup win over Regionalliga side Eintracht Trier were useful indicators for their ability to cope with pressure.

In both instances, Tuchel opted for the rather sturdy midfield duo of Sebastian Rode and Gonzalo Castro. Both don't excel as playmakers but have the physicality and intelligence to survive a midfield battle. Dortmund created a number of chances against Bayern through counter-pressing, and the same could be needed against Mainz.

Their more creative midfielders Julian Weigl and Mario Gotze, who are able to evade pressure more than taking it head-on, are unlikely to feature, with the former looking pretty far off his best form in a friendly against Hallescher FC on Tuesday and returnee Gotze missing both the friendly and the cup match with muscle problems. 

Seeing as their pressing-resistant midfielders will likely sit on the bench—new signing Raphael Guerreiro is also unlikely to feature in the starting XI—Dortmund may well opt to accept Mainz's invitation for a physical battle in the middle of the park and hope that individual quality will set the teams apart.

How to Cover Against Mainz's Counter-Attacks

Mainz's attacking strategy goes hand in hand with their pressing. Whenever they dispossess the opponent, they try to get forward in numbers and run at an unorganised, often shorthanded defence.

The graphic below from an impressive 4-0 pre-season win over Liverpool illustrates how the Zerofivers can overwhelm an opposing back line in counter-attacking situations:

WyScout

Tactics blogger Dustin Ward noted for StatsBomb.com that Mainz's average shot location was the second closest to goal in the Bundesliga, behind only Dortmund, meaning they manage to finish their counter-attacks in dangerous positions.

He further pointed out that the Zerofivers "had the third-fewest [pass] completions in attacking areas in the league," highlighting a directness that can hurt teams that are dominant on the ball and commit many players going forward—it's no coincidence that Mainz were the only Bundesliga team to beat Bayern in Allianz Arena last season.

For Dortmund, this means they need to be on high alert. They have two of the quickest centre-backs in recent memory in Sokratis Papastathopoulos and Marc Bartra, which will help, but Tuchel may be well advised to help them out by ordering his full-backs to position themselves deeper on the pitch.

The 42-year-old fixed his defensive issues from the first half of his maiden campaign at the Westfalenstadion partly by committing fewer men forward. Dortmund conceded only 11 goals after the winter break, compared to 23 in the first 17 matches of the season.

Another wrinkle that helped fix their leaky defence was to play with three central defenders in a number of games. The Black and Yellows naturally had more stability and defensive cover with right-back Lukasz Piszczek moving inside and athletic runner Erik Durm playing at wing-back.

Dortmund rarely tested this system in pre-season, however.

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It's more probable that Tuchel tells his full-backs not to venture too high up the pitch and his wingers to work back with diligence. He lauded club-record signing Andre Schurrle for just that after the cup win, per the club's official website: "There are not many offensive players who are also defined by their defensive play and have a very small ego. That's why we absolutely wanted to sign him."

On the other wing, however, 19-year-old Ousmane Dembele has a lot to learn in terms of his defensive contribution. It wouldn't be too surprising to see a more senior option play in his stead, with Adrian Ramos the most likely option after starting in the Supercup.

Depending on how much Tuchel fears Mainz's counter-attacks, he could also move right-back Felix Passlack forward and play him ahead of Piszczek.

Lars Pollmann also writes for YellowWallPod.com. You can follow him on Twitter.