Arsenal's Europa League campaign came to an end in the Wanda Metropolitano Stadium on Thursday night.
Atletico Madrid ran out 2-1 winners on aggregate, with former Chelsea striker Diego Costa scoring the only goal in the second leg of their semi-final
It was Arsene Wenger's final opportunity to win silverware as Arsenal manager, after 22 years in charge.
“I am like the team, very sad and very disappointed, even very frustrated,” the 68-year-old said.
Asked about his future plans, Wenger said: “I have to recover first from a huge disappointment. I’m very, very sad to leave the club with that exit.
"It is very difficult to take but there are some good ingredients in our team and they will bounce back."
Wenger is set to leave at the conclusion of the 2017/18 season.
Mustafi and Wenger
Journalists - James Olley and Mark Mann-Bryans - inside the Wanda Metropolitano spotted a conversation between Wenger and Shkodran Mustafi as the match entered the 90th minute.
Arsenal had nothing to lose and desperately needed a goal to send the game to extra time - and the German defender reportedly asked his manager if he could go up front.
It's bizarre that Mustafi was told to stay back.
Arsenal has one shot on target all night and needed to find a late equaliser to keep their Europa League dreams alive.
Mustafi was signed from Valencia for £35m in 2016 - but has been regularly criticised for his sub-par defending.
Meanwhile, Diego Simeone's Atletico Madrid will face Marseille in the Europa League final on May 16.
"We are delighted to be there in the final, we've wanted to be back in a final ever since the last one we reached," said the 48-year-old Argentine coach.
"The side responded so well last week, they suffered, [goalkeeper Jan] Oblak had a great game – but that's what happens on these big nights, big players stand up to be counted and the team were up there with him at that level.
"We worked well this week and we felt good going into tonight."
Simeone is one of the candidates to replace Wenger but Arsenal may struggle to convince him to leave Atletico for north London.
The Gunners currently lie sixth in the Premier League table and won't be taking part in the Champions League next season.