Nacho Monreal has warned that Arsenal cannot win the Premier League title unless their defending improves, and admitted that the “atmosphere is bit nervous” after successive defeats.

The Gunners face Bournemouth at Emirates Stadium on Saturday having shipped eight goals in their opening three fixtures.

Arsene Wenger’s side recovered from 3-2 down to beat Leicester 4-3 to kick off the campaign, but they succumbed 1-0 at Stoke before a 4-0 thrashing at Liverpool.

Monreal said Arsenal will persevere with the 3-4-2-1 system which enabled them to win nine of their final 10 games in all competitions last season — including the FA Cup Final — but need to tighten up at the back.

“I have to say that in the last three games we have conceded eight goals and this is a lot,” he said.

“Obviously it is not only the fault of the defenders. Every single player has to defend, but conceding eight goals in three games is a lot and we have to improve. We can’t concede three or four goals because it is then impossible to get something.

“In this moment, everything is a bit difficult, because after losing the last two games, you have talks about how to play and not. In the past, playing with this shape, last season for example, we won games.

“This year we won the Community Shield. The problem is the last two games we lost and the atmosphere is a bit nervous, but I think from tomorrow if we play a good game and get three points, we will have more confidence and we will improve.

“We need to improve a lot. Our target is to win the Premier League, and obviously we can’t win it if we keep playing like we did against Liverpool.”

Monreal hailed the return of Alexis Sanchez, who remains at Arsenal after a proposed £60million move to Manchester City collapsed on deadline day as the Gunners failed to sign Monaco winger Thomas Lemar.

Sanchez’s state of mind has been questioned, but the Spain international said: “It is good news for us, the fans, and the club in general. He is the most important player for us and all we can offer to the fans is that in the next game, from the first minute, we start with intensity and play a good game and everything will come back as before.

“Alexis is always trying to win, he always helps us and gives his maximum, 100 per cent effort in every single training session and he is going to be very important to us for the rest of the season.”

In contrast to several other players, including Sanchez and Mesut Ozil, running down their existing contracts, Monreal revealed he would like to retire at Arsenal.

The 31-year-old, who joined in 2013 from Malaga, said: “I would like to [finish my career here]. I feel really good playing for Arsenal. It is an amazing club and I would like to stay.

“I have two more years [on my contract] and we will see what happens in the future. At the moment I am focusing on Arsenal, on Bournemouth and I want to win the next game. That is all I am thinking.”