Mikel Arteta has told Arsenal it is "time to evolve" as he looks ahead to what could be a crucial transfer window for the club.

A 2-1 aggregate defeat to Villarreal in the Europa League semi-finals means the Gunners' season looks set to end in hugely disappointing fashion.

They are ninth in the Premier League with three games to go and could well fail to qualify for European competition for the first time since they were absent in 1995-96, with their domestic cup challenges having ended in December and January.

Pressure has been mounting on the manager given their apparent lack of progress, and Arteta accepts they must now build on the institutional changes at Emirates Stadium by creating a team capable of competing with the best again.

"We have already had an incredible amount of changes throughout the club in the last year or so. More than ever," Arteta said on Tuesday.

"We are looking to improve and we're looking to be much closer [than] where we are at the moment. I know there are certain things we have to improve.

"Now, it's how we evolve. There's a lot of things that have to be done, and they have [been] done. A lot of changes to make and a lot of them have been made. Now, it's time to evolve.

"We have made progression in many areas, I would say performance included, and that's supported by many factors we have looked at. Results-wise, to where we want to be, it has to be improved.

"We have to do better. We have to be more consistent, we have to win more games and in order to do that, there are certain things that have to improve.

"We'll see what happens in the summer."

The Gunners have faced heavy criticism from fans, pundits and ex-players this season, including recently from former defender Martin Keown, who claimed the club are "going backwards".

Arteta believes plenty of good work has been done behind the scenes but accepts he will only ever be judged on results.

He said: "I think everybody is entitled to speak their opinions. I cannot control that. If you tell me what I would like to have around the team and everything related to the football club, it's that we have the unity and stability to work, but if this is not the case, there's nothing I can do.

"The only way I can improve that is by having a team that performs on the pitch and makes them proud. That's the only thing I can do.

"The only thing I have to be judged on is: do I create the necessary environment for a top, elite team to perform at the highest level, and get everybody in the condition to do their best? And after that: do I get the best out of the players that I have? The maximum, whatever the level is – do I get the best out of that? This is how I judge myself. Outside, the way I'm going to be judged is with results, nothing else. That we've done good before in the past, with the process, it's irrelevant. It's only what you get from that result when you're on that pitch."

Arteta says he has spoken regularly with technical director Edu this season about the club's plans to strengthen the team, particularly in the coming transfer window.

"There are so many things to do because we have a lot of players on loan, a lot of players with contracts still that we have to sort, and it will depend on what happens with a lot of those players and what we are able to recruit to improve the team is going to determine where we are," Arteta said.

"We've been sitting down the whole year, we've been in constant communication, and things will change. Some things will stick to the plan that we already have and some other things will come out. But we sit down very regularly to talk about those things."

Arsenal face Chelsea on Wednesday knowing that a defeat could well prove a fatal blow to their chances of finishing in a Europa League spot. They are four points behind north London rivals Tottenham, who sit seventh.

Still, Arteta can see the silver lining of a season in which he will not have to prepare his team to play once every three days for months on end.

"I think having a pre-season is going to be really helpful because we haven't had any time to work together since we arrived," he said. "After that, let's see where we finish this season and how many games we have to play, but obviously, in terms of game preparation and time to coach, it's much better to be in that position."

One positive in Arsenal's season has been the progress made by young players such as Bukayo Saka and Emile Smith Rowe, and Arteta has no doubt about placing them at the centre of his project.

"Absolutely. They've shown that this season they are ready to take responsibility in important moments," he said.

"They have the right senior players around them to help as well. It's about how we click, and that we are consistent because we've shown on the day that we can compete and beat the top teams, but through 38 games [in the Premier League season], we haven't done it. In the Europa League, we've done it to the point where we were so close to getting to the final, but in 38 games, that's the duty that we have and the challenge we have ahead of us: to compete with the big teams."