It has not taken long for Arsenal's squad to start creaking under the weight of the much-criticised schedule.
Still missing Bukayo Saka and Martin Odegaard, as well as full-backs Jurrien Timber and Takehiro Tomiyasu, Arsenal continued their steady progress through the Champions League with a 1-0 win over Shakhtar Donetsk on Tuesday, but it will have come at a price if their injury list lengthens.
Mikel Arteta insisted that the decision to replace Ben White, who had been booked, was tactical - "We’ve played enough with 10 men in recent periods," he said - but Riccardo Calafiori was forced off in the second half after appearing to jar his knee.
"He felt something, I don’t know the extent of it so in that sense not great news," said Arteta, who added that Calafiori's situation was "a worry".
Arsenal host league leaders Liverpool on Sunday and, if Calafiori is out, Arteta is facing a major problem in both full-back positions, assuming neither Timber nor Tomiyasu makes a surprise return.
Arsenal will already be without suspended centre-half William Saliba for the six-pointer following his straight red card in the defeat at Bournemouth, meaning White will likely deputise at centre-half with Thomas Partey filling in at right-back.
Partey played the second half at right-back against Shakhtar following Mikel Merino's introduction for White, in what appeared to be a dry run for Sunday's game.
Partey is comfortable playing full-back, particularly when he inverts into midfield, but the 31-year-old is not quick, which should offer encouragement to Luis Diaz, who is likely to patrol Liverpool's left side.
More concerning for Arteta, though, is who will face up to the top-flight’s deadliest wide player, Mohamed Salah, on the opposite flank.
Arsenal are not short of options, although none is especially convincing. Myles Lewis-Skelly, a teenage midfielder who has been converted to full-back, replaced Calafiori against the Ukrainian giants but it would be an enormous challenge for the 18-year-old to be tasked with stopping Salah.
Oleksandr Zinchenko is an experienced option but defensively suspect, while Jakub Kiwior has also tended to struggle, his latest mistake coming with a limp back-pass to play David Raya into trouble ahead of Bourneouth's second goal at the weekend.
Stopping Salah does not guarantee stopping Liverpool but if Arsenal fail to deal with the Egyptian convincingly, it is hard to see how they will not finish the weekend seven points behind their title rivals.
Arteta also confirmed afterwards that Odegaard, his captain, would not be fit to return to the side for Sunday's visit of league leaders Liverpool, while he was less definitive on Saka, who should nonetheless be considered a doubt at this stage after picking up a muscle problem on England duty.
Arsenal have understandably looked short of creative spark without Odegaard, while their reliance on Saka for cutting edge was again underlined on Tuesday.
Leandro Trossard's limp second-half penalty, which was saved by the legs of Dmytro Riznyk, summed up their finishing on the night, as they failed to build on Riznyk's own goal after 29 minutes.
Gabriel Jesus, deputising for Saka, was characteristically wasteful, firing a glorious opportunity too close to the goalkeeper in the first half, and squandering further promising positions from the right flank before he was replaced by Raheem Sterling with 20 minutes remaining.
The Brazilian is an experienced head but has not scored since January 30, a concerning run even considering his injury lay-offs in that time.
It is not yet clear, meanwhile, what summer signing Sterling can offer as an alternative for Saka after he was the fall guy at Bournemouth, hooked in the first half following Saliba's dismissal.
Kai Havertz's form and a bright performance from Gabriel Martinelli, who forced the own goal when his shot came back off the post and struck Riznyk, is encouraging, but Arteta's squad will continue to look stretched up front until Saka returns.
Arsenal's depth has long felt like a dividing line between them and Manchester City or even Liverpool, who arguably bost more variety in forward areas than any other side of the league.
Arsenal have taken baby steps to address the issue but, as another big game looms, they look a little depleted, leaving Arteta facing several headaches this week.
