Stuttgart, which won the Bundesliga in 2007, was relegated in 2016 but bounced straight back by winning the second division last season.
The club has made a number of signings in an attempt to stay in the top flight this time: former Germany defenders Holger Badstuber and Dennis Aogo; Brazilian defender Ailton; forwards Chadrac Akolo and Anastasios Donis; and Germany backup goalkeeper Ron-Robert Zieler.
Arguably more significant, however, was Stuttgart's luring of Michael Reschke from Bayern Munich to be its sporting director. The 59-year-old Reschke has a good reputation for scouting and player development after three years at Bayern and 10 at Bayer Leverkusen. His services will be appreciated at a club that has long nurtured raw talent. Seven members of Germany's Confederations Cup-winning squad began their careers at Stuttgart, including Timo Werner, Joshua Kimmich and Mario Gomez.
Simon Terodde, the team's top goalscorer last season, knows his side faces a difficult task to ensure survival this year.
"In the second division we were always the favorites, had a lot of ball-possession," Terodde said. "That will change now in the Bundesliga when you're playing against the big teams like Schalke, Bayern, Dortmund. That's the way it is. But still, we're prepared."
Hannover also returned at the first attempt, as the runner-up in the second division.
But the side's summer rebuilding has been overshadowed by club president's Martin Kind's takeover of voting rights. Kind has been an outspoken critic of the Bundesliga's 50-plus-1 regulation, which limits the influence of external backers, and he was able to increase his stake to a majority thanks to an exemption as he has backed the club for 20 years.
The regulation prohibits stakeholders from having more than 49 percent of a club, with the rest remaining in club members' hands to prevent takeovers. There are exceptions — Wolfsburg, Leverkusen, Hoffenheim and now, Hannover.
The move has been opposed by many club supporters and Kind has been the subject of derogatory chants at friendly games. Hannover's friendly at Premier League side Burnley was called off at halftime due to trouble from the visiting fans.
The club has been relatively quiet on the transfer front, bringing in defenders Julian Korb and Matthias Ostrzolek from Bundesliga rivals Borussia Moenchengladbach and Hamburger SV, respectively, as well as midfielder Pirmin Schwegler from Hoffenheim.
Staying in the Bundesliga is the initial priority, though Kind wants the club to play internationally.
Horst Heldt was appointed as sporting director last March, and he brought in Andre Breitenreiter as coach. The two had worked together at Schalke.
"We need three years to establish ourselves back in the Bundesliga, and then we will look forwards," Kind said. "I can't say yet whether that will be Europe."
More AP German soccer: www.apnews.com/tag/Bundesliga