chalke 04's training camp in Turkey ahead of next week's Bundesliga restart did little to prop up their confidence with the last-placed club having failed to win any of their five friendly matches so far. Their 1-0 loss to Nuremberg on Tuesday ahead of Wednesday's return to Germany had been preceded by four other failed attempts for a win: 2-2 draws against Zurich, Rapid Vienna, and third-tier club Osnabrueck and defeat by Hajduk Split. "I keep saying that we need the team should reduce mistakes," Schalke coach Thomas Reis said following Tuesday's loss. "But then it is again a mistake from a young player that leads to the goal (for Nuremberg). We just cannot present ourselves like that ".For player Kenan Karaman it is inexplicable why Schalke's form can fluctuate wildly during a single game. Kenan Karaman did not find an explanation for the fluctuation of Schalke's level significantly during one match. "We played two completely different halves and that couldn't happen," the forward said. "I feel angry and I take responsibility for that." Schalke coach Thomas Reis said. "We changed 11 players and then show a different face, even though we train hard and know the game plan. Then we make a stupid mistake and we are not good enough to defend." Schalke was promoted to the top flight last season after a sudden relegation a year ago, but he is struggling in the league after achieving only two victories in 15 matches. Schalke has a friendly match against Werder Bremen before the Bundesliga resumes next week, when the team will travel to face Eintracht Frankfurt, which is participating in the Champions League.