Alexis Sanchez believes Arsenal "lack self-belief" to become Barclays Premier League champions this season.
The Gunners blew a big chance to increase the pressure on leaders Leicester when they were beaten at home 2-1 by Swansea last night.
Joel Campbell had opened the scoring for Arsenal, who also hit the woodwork on three occasions, but goals from Wayne Routledge and Ashley Williams saw Swansea leave the Emirates Stadium with all three points for the third time in four years.
It was a much-changed Swans line-up, showing six alterations from the weekend defeat to Tottenham and with more than an eye on a crunch match at home to fellow strugglers Norwich on Saturday.
They picked up the win without head coach Francesco Guidolin, who was admitted to a London hospital with a chest infection, but still managed to dent both Arsenal's confidence and their title hopes.
And Sanchez, who hit the post in the first half before cracking a second-half free-kick against the crossbar, feels it is the confidence of the squad that has seen them embark on a damaging run of just three wins from 11 games in all competitions.
We need to step out onto the pitch as if we're already 1-0 up
"We lack self-belief, that we can actually be champions," he told Directv Sports.
"I think we can win the Premier League with the players we have. That said, we lack a certain hunger. We need to step out onto the pitch as if we're already 1-0 up.
"I remember a game against Manchester United last year. The lads looked hungry for silverware as we took to the pitch.
"We crushed them in the first 20 minutes and went 3-0 up. We were hungry and brimming with confidence that day."
Williams, who has scored the decisive goal in two of Swansea's last three league wins, has now called on his side to make their victory at Arsenal count by beating Norwich.
The Canaries are 18th having lost eight of their last nine games in all competitions and are now six points adrift of the Swans, with captain Williams issuing a rallying cry to his side.
"The win is massive," he said.
"We seem to enjoy coming here for whatever reason but we need points from all places now and nobody thought we would get them here.
"They were all looking at the next three games but, by winning here, we try and build on it and go into Norwich - if we don't win there and back up the win then we are back at square one.
"Hopefully this gives us enough confidence to know we can get results anywhere. We can go and beat a team challenging for the title so we can beat anyone on our night."
Looking for just their second back-to-back league wins of the season, Williams insists even adding another three points on Saturday does not make them safe.
"I don't think 33 points would be enough but it would go a long way," he added.
"Every point or three points we get now on is massive - we are going out to win games as we should be doing but even if we win Saturday we know it is not job done."