Arsenal's failure to address key problem area that affected Champions League pursuit

Arsenal began the season with five players who could feasibly play at right-back, so it made sense for Mikel Arteta to offload some of his fringe options.

But the Spaniard may be regretting some of those choices as the Gunners face the agony of missing out on a top-four finish in the Premier League after losing 2-0 to Newcastle United on Monday. Takehiro Tomiyasu, Cedric Soares, Calum Chambers, Ainsley Maitland-Niles and Hector Bellerin all started the season at the Emirates Stadium able to fill in the role.

However, it was clear that once Arteta had pushed through the £16million deal to bring in Tomiyasu from Bologna, the likes of Chambers and Bellerin would be left out in the cold. Sure enough, the latter joined Real Betis on loan until the end of the season, while Chambers was retained as a backup option.

The versatile Maitland-Niles became frustrated with his lack of game time in the first half of the season and subsequently moved to Roma on loan until the end of the season. Then, when it emerged that Arsenal could save £2m in wages by allowing Chambers to terminate his deal and sign for Aston Villa, the club had no hesitation. But perhaps there should have been, for those decisions left Arteta suddenly very short at the back and also at the most congested stage of the season.

It was no surprise that Tomiyasu, who had featured in every game since his arrival, pulled up with an injury. Cedric Soares was drafted in and the Portuguese did an adequate job, but for a club supposedly challenging for the top four, it represented a weakness in the side. Even when Tomiyasu returned from his recurring calf problem, Arteta was forced to deploy him at left-back to deputise for Kieran Tierney. Concerns over the ability of