He was ok first half - certainly better than several others.
Dreadful second half - but it was obvious he was going to be as soon as you saw that he was playing in that more advanced position.
Yep, notice how much we start hoofing it without Yaya deep to take the ball from the defence and he's useless in that advanced position now, he hasn't got the legs to get away from players in the final third anymore.
To be fair to him he forced the move that led to the winner.