William Saliba has returned to first-team training for Arsenal, presenting manager Mikel Arteta with a significant defensive selection dilemma. Saliba, a crucial player in Arsenal's title charge last season, has been sidelined with a back injury sustained during the World Cup.

In Saliba's absence, summer signing Ezri Konsa has stepped into the defense, forming a formidable partnership with Gabriel Magalhaes. This pairing has helped Arsenal maintain the league's tightest defense, conceding only five goals in nine games. Konsa's seamless integration has been lauded, with some suggesting his partnership with Gabriel is among the best in world football.

Saliba had been managing his back issue throughout last season before consulting a specialist after the World Cup. He underwent a lengthy rehabilitation period without requiring surgery. While he had been training individually, his return to full training ahead of Arsenal's Champions League match and a busy festive schedule means Arteta must now make difficult choices regarding his backline.

Before Konsa's arrival for £55 million, Arsenal already possessed several senior defenders, including the established Saliba-Gabriel partnership. Konsa, however, has been a standout performer this season, starting seven of Arsenal's nine Premier League matches. Arteta has described his settling-in period as "unbelievable." The 29-year-old defender joined from Aston Villa, where he made 286 appearances and won the Europa League. He has also established himself as a first-choice player for England, starting multiple games at the World Cup, including a quarter-final match at right-back.

Konsa's physicality, speed, and aggression have impressed supporters. He scored the opening goal in Arsenal's 2-0 victory against Everton and delivered another commanding performance in the win against Liverpool.

With Saliba's return, the competition for places intensifies. Ben White and Jurrien Timber have been the primary right-backs this season and are reliable options. Konsa could potentially shift to right-back, a position he has played for England, allowing Saliba to resume his partnership with Gabriel. Arteta's emphasis on physicality could also see Konsa deployed at right-back to create a formidable defensive challenge for opponents. The increased competition may also limit game time for younger defenders like Cristhian Mosquera.

Given Arsenal's extensive fixture list last season and Arteta's ambitions for domestic and European success this season, the depth of options in defense will be crucial for managing player rotation.