Stuttgart, home to Japan midfielder Wataru Endo and defender Hiroki Ito, sacked manager Pellegrino Matarazzo on Monday, who left the club without a win after nine games in the German first division.
On a busy weekend for Japanese players in Europe, Sporting Lisbon midfielder Hidemasa Morita scored for the second straight league game while defender Yukinari Sugawara grabbed his season's first league goal for AZ Alkmaar.
Stuttgart lost 1-0 at home to leaders Union Berlin, who had Genki Haraguchi starting for the first time in seven games. Paul Jaeckel scored the 76th-minute winner to leave Stuttgart in 17th following five draws and four defeats in the Bundesliga.