England captain John Terry heads a lengthy injury list that threatens to hinder the start of Chelsea's season.
Terry could miss England's next two Euro 2008 qualifiers
Defender Terry, 26, may be out for a month after damaging knee ligaments in training and missing Sunday's Community Shield defeat by Manchester United.
Didier Drogba, Claude Makelele, Salomon Kalou, Michael Ballack, Andriy Shevchenko, Wayne Bridge and Paolo Ferreira were also out of the squad.
"It was not easy to prepare for this game," said Blues boss Jose Mourinho.
Chelsea played Joe Cole as a lone striker against United, with summer signing Tal Ben Haim partnering Ricardo Carvalho at the heart of defence in a match the Blues lost on penalties.
Striker Claudio Pizarro, who arrived on a free transfer from Bayern Munich in June, is struggling with a back problem.
And Mourinho's predicament was not helped by keeper Petr Cech, Glen Johnson, Florent Malouda and Shaun Wright-Phillips all picking up injuries before half-time against United.
They carried on but Chelsea will assess the extent of the damage to a growing number of players this week in the lead up to the opening game of the Premier League season against Birmingham on Sunday.
Terry's injury appears to be the main concern and is believed to have suffered the knee problem in training on Saturday.
He could miss the league games against Birmingham, Reading and Liverpool.
When the injured players are back, they are back - But I am ready to go to the fight with the boys who played
Chelsea boss Jose Mourinho
England boss Steve McClaren may also have to manage without his inspirational leader for the friendly with Germany on 22 August as well as the crucial Euro 2008 qualifiers against Israel and Russia in September.
Mourinho could also soon be without winger Robben and German captain Ballack, who, despite injury concerns, have also both reportedly been the subject of offers from Real Madrid.
"I am very happy with the players who took part," said Mourinho, who refused to be drawn on the issues surrounding his squad.
"When you ask me about John Terry and Didier Drogba or Michael Ballack, Salomon Kalou or Claude Makelele - all of the boys who were not here - I don't want to go in that direction because I want to respect the players I had against Manchester United.
"They played very well for me and I prefer to speak about them instead of the players not involved in the game.
"I now have to analyse the picture for the next two weeks to make my decisions in relation to the three matches we have to play against Birmingham, Reading and Liverpool."
However, Mourinho insisted he was ready for the new campaign and insisted: "When the injured players are back, they are back. But I am ready to go, like I was on Sunday, ready to go to the fight with the boys who played.
"I am happy with them. I work with them, I play with them and I trust them, so no problems."