Cacau, Marc-Andre ter Stegen, Sven Bender and Julian Draxler have all been left out of Germany coach Joachim Low's final 23-man selection for Euro 2012.
Low announced his squad early on Monday, with the quartet flying back to Germany immediately.
The Germany coach, who took a 27-man squad into two training camps in Sardinia and France, will explain his choices on Tuesday when he will be working with his final group in the build-up to their first match of the tournament against Portugal on June 9.
Stuttgart striker Cacau is a surprise exclusion as Low now takes only three forwards with him to Poland and Ukraine - Mario Gomez, Miroslav Klose and Lukas Podolski.
"It was my big goal after the World Cup in South Africa (in 2010) also to be part of Euro 2012 with the Germany national team," Cacau said.
"I knew from the beginning that the competition for the 23 places would be hard and tight.
"I gave it my best shot. Like the younger players, I am also disappointed, but I still feel ...