Schalke captain Benedikt Howedes believes the club's summer signings will bring a new mentality to the club.
The Germany international, 25, told kicker that the Royal Blues, who finished fourth in the Bundesliga last season, had "absolutely reinforced our team".
Schalke's summer transfer dealings have been widely acclaimed as among the best in Germany, with some tipping them to be title outsiders next season.
They have added Mainz striker Adam Szalai, youngsters Leon Goretzka and Christian Clemens and former Dortmund centre-back Felipe Santana, and have also hung on to 19-year-old Germany international Julian Draxler.
Rising midfield star Draxler confirmed he had turned down offers from La Liga and Premier League clubs.
"Competition will intensify," Howedes said. "That's exactly what was sometimes missing last season, also because of injuries. Nobody will be able to sit back now. Everyone has to give their all in training."
Howedes added that complacency had been a flaw last season, explaining: "We did not have a final punch in some situations. We might have finished fourth, and should not talk that down. But in decisive moments we should have been more clinical."
He said he believed Draxler had made the right decision to stay, adding: "He is a key player and will grow in character.
"Of course, he is still really young - but he is able to dictate the direction of games."
He said "the potential is there" for another top-four finish, but warned: "We have to prove we can be more consistent."