Arsenal midfielder Santi Cazorla was taken off at half time during the North London Derby due to a mystery illness. The Spaniard said he felt dizzy during the 1-1 draw, with boss Arsene Wenger saying he was operating at "around 30%".
"He's not sick, he just was dizzy and he couldn't move. I didn't really know what he had. So at half-time I took him off, I hope it is nothing bad. He says he is alright now," Wenger added.
The Gunners were held to a draw by arch rivals Tottenham Hotspur on 8 November at the Emirates. Harry Kane opened the scoring in the first half, before Kieran Gibbs equalised in the second.
Wenger praised his team's mental strength, after coming back from goal down, and recovering from a 5-1 thrashing at Bayern Munich in the Champions League on 4 November.
He said, "We have shown character again today, in that we were a bit on the ropes. We responded and every time that we have a disappointment the game after I feel we respond well.
"When you look at the results again today you see [Aston] Villa and [Manchester] City 0-0, Liverpool lost, we played 1-1, it just shows you that the championship will be extremely difficult for everybody and that mental qualities can have a big influence," Wenger added.
The draw leaves Spurs in 5th place, with Arsenal five points above them in second.