(Reuters) - Chelsea coach Thomas Tuchel said he had taken off Andreas Christensen at halftime of their 4-2 defeat by Arsenal on Wednesday because he was unable to continue, not due to his error that led to the visitors' opener.
Arsenal got off the mark when Eddie Nketiah pounced on a weak back pass by Christensen before slotting past goalkeeper Edouard Mendy in the 13th minute of their Premier League match at Stamford Bridge.
Danish defender Christensen was then replaced by Thiago Silva during the break.
"He said he cannot continue, so I think he had some problems," Tuchel told reporters. "I don't take a player out because he makes one mistake.
"To say the pitch is difficult to play here, it maybe sounds like an excuse. But it is a very, very difficult pitch that we have here. The ball bounces very awkwardly in front of Andreas when he wants to play this ball.
"But still, we had the same mistake against Real Madrid that cost us the next round of the Champions League, and this one cost us the next match."
Christensen took the blame for the goal but said Chelsea continued to make mistakes even after Timo Werner had got them back on level terms.
"I take 100% responsibility on my shoulders for the first goal, it was my mistake, but luckily for me we got back into the game quite quickly through Timo's goal," Christensen said.
"We kept making mistakes though and it's hard to keep bouncing back. We can only blame ourselves for this result."
Chelsea remain third on 62 points, five points ahead of Tottenham Hotspur and Arsenal having played one game less. They host West Ham United on Sunday.