Arsenal boss Mikel Arteta admits changes must be made after their title collapse.
Their 3-0 home defeat effectively handed the Premier League race to Manchester City on Sunday.
Arteta said, "I'm responsible for what happened today. My job is to get the best out of every single individual that we have. And if we have to take it there (pretends to shoot himself) for ten and a half months, we have to and they have to. I have tried to do that with my best ability but today obviously I didn't do it.
"My thinking is exactly the same. Obviously what the team has done over the last ten months is very different to what anybody expected and that generates a lot of expectation as well enthusiasm, happiness and joy. That's something that has to be managed in the right way and after we have the responsibility to make sure the team performs and I am responsible for that.
"So I hate the feeling of letting people down when they are expecting something. That's the biggest regret I have today and I have to apologise for that."
Asked if City winning at Everton earlier in the day had an effect, Arteta also said: "I don't know. This cannot be the way to justify what happened in the second half because in the first half it didn't happen.
"It was very interrupted and there was a lack of flow and there were a lot of duels because it was a man to man game. In the second half we lost certain things, we lost focus, we lost pairs and it became a really difficult game to play."