Arsenal captain Martin Odegaard has insisted "we can't feel sorry for ourselves" and must move on quickly following their stunning loss away to fourth-tier Fleetwood in the League Cup.

The Premier League champions crashed out 5-3 on penalties in an incredible upset after the fourth-round tie finished 1-1 in normal time at Fleetwood's home ground of Highbury.

Arsenal's Bruno Guimaraes had his penalty saved by Jay Lynch in the shoot-out before teenage defender Conor Haughey scored Fleetwood's winner.

Aaron Loupalo-Bi's first-half goal had put Fleetwood ahead before Viktor Gyokeres equalised after the interval.

Arsenal manager Mikel Arteta made nine changes to his starting side but after a ragged first-half display he sent Norway midfielder Odegaard on for the second period.

The visitors, last season's losing finalists, managed an improved performance but still missed several chances before teenage rising star Max Dowman was sent off five minutes from the end of normal time.

"It's very frustrating to go out," Odegaard said after Fleetwood made a mockery of the 84 places between the clubs in the English football pyramid.

"Obviously, the way we've played was not on the level. We need to do much, much better than we did.

"Frustrating, but congratulations to Fleetwood and we look forward to the next game already and bounce back.

"They did well so we have to give them credit, but... we need to do better. I thought we improved during the game, but again, we need to step up even more – so that's a shame."

Arsenal now just have days to get the defeat out of their system ahead of what promises to be a tough match at Liverpool on Sunday, with the Gunners having drawn level on points with Premier League leaders Manchester City last weekend.

"We can't feel sorry for ourselves. We need to move on – we have a big game at the weekend, so bouncing back at the weekend is all we can do now," Odegaard added.

Meanwhile, British media reports Wednesday said Arsenal would lodge an appeal against Dowman's red card with the Football Association and were hopeful of a decision being handed down prior to the trip to Anfield.

The 16-year-old was dismissed for kicking out at Harrison Neal following a heavy challenge by the Fleetwood midfielder, with an unimpressed Arteta giving Dowman a strong word as he trudged off.

"Something that we discussed already before the match," Arteta said when asked what he told Dowman.