The European champions were dealt a massive injury blow minutes before the start of the game after a test revealed a groin problem for defender Antoinio Rudiger.
Rudiger has played 28 league games this season and his absence, if long term, will be a massive blow to Chelsea, who still have third place to wrap up and the small matter of an FA Cup final against Liverpool.
The Champions League-winning manager said: “ We conceded seven with Toni, this answers the questions about his absence and so this is not an individual issue.
“So it’s again for the players when they do well and they have to take it collectively.
“I see these mistakes quite often and it can not continue this way, its not because Toni was not here today because he could not.”
Andreas Christensen nightmare start and withdrawal
Andreas Christensen had a nightmare of a start to the game against Arsenal, as it was his under hit pass that Eddie Nketiah pounced on to give Arsenal the lead in the game.
After that he had quite a below par performance, and was then withdrawn after the first half and replaced with the ever-green Thiago Silva.
The change had a suspicion of both being tactical and enforced by injury, so Tuchel took advantage of the post-match press conference to make clear that the Danish defender informed him that he could not continue and that was why he was replaced.
The Chelsea manager added: “ He said he cannot continue and that is why I took him out. I don’t take a player out because of one mistake.
“To say that the pitch is not in our favour and we made a mistake against Real Madrid, but yeah he said he can not continue.”