Arsenal's Champions League ambitions have hit a major obstacle, with a growing injury crisis casting a shadow over their crucial quarter-final second leg against Sporting Lisbon. The most concerning absence from Tuesday's open training session was midfield linchpin Declan Rice, whose presence has been vital to the Gunners' success this season.

Rice's situation is particularly worrying given his recent workload. After returning from an international break issue to captain the side in a surprising Premier League defeat to Bournemouth, his non-participation in final preparations suggests a potential setback. He is far from alone in the treatment room, however, as Arsenal's depth is being severely tested.

The injury list reads like a who's who of Arsenal's core. Bukayo Saka has now missed three consecutive matches, while captain Martin Ødegaard continues to battle fitness concerns that also kept him out of the Bournemouth loss. Defensive stalwart Jurrien Timber hasn't featured in a month, further depleting Mikel Arteta's options ahead of a season-defining week.

This comes at a worst possible time. Arsenal travel to the Emirates holding only a slender one-goal advantage from the first leg, thanks to Kai Havertz's dramatic injury-time winner. The team is also looking to bounce back immediately from a league defeat that allowed Manchester City to close the gap at the top to just six points.

The schedule is unforgiving. After Wednesday's high-stakes European night, a monumental Premier League title showdown at the Etihad against Manchester City awaits on Sunday. Yet, to keep their double-chase alive, Arsenal must first navigate past a dangerous Sporting side. The Gunners' impressive unbeaten run in Europe this season, which includes wins over giants like Bayern Munich, will be put to its sternest test yet by this wave of absences.