After the chaos and cavorting came the cold-blooded calculations. Nobody of an Arsenal stripe was in a rush to let the headiness of Saturday’s momentous comeback against Bournemouth subside but, when it did, the fretfulness that lurks just beneath the surface of most clubs’ fanbases reared its head. The rest of their campaign may come to resemble a Europa League sandwich and, with the precious gift of an improbable five-point lead in the Premier League looking too delicious to relinquish, the question was predictable: would it not be better for Mikel Arteta to ditch any quest for continental honours and go for broke at home? Arteta has already said that he will not sacrifice a tilt at Europe and, judging by the lineups he fielded in the group stage, it would be wise to take him at his word. They have not travelled light for their first knockout tie of the year. Arsenal arrived in Lisbon with a strong squad and assertions from their manager that winning is infectious. “If we play well and are able to win the game, for sure we’ll be able to prepare better for the next game,” he said, indirectly referring to the exacting test that should await at Fulham on Sunday. The opposing schools of thought both make sense in their way. The brickbats would rain down if Bukayo Saka started at Estadio José Alvalade in the last 16 first leg against Sporting, as he probably will, and sustained an injury with far-reaching consequences; Arteta prefers the conviction that momentum can never be too intoxicating and believes the quest for a first European trophy in 29 years can further invigorate their title chase. Part of the logic for retaining a healthy number of regulars is that fielding essentially separate sides for league and cup would not necessarily promote unity or send the right message. Arteta does not want anyone to see himself as a second-stringer: everyone can be needed at any moment, as the hitherto marginalised Reiss Nelson proved so spectacularly last weekend. “We have one team,” he stressed. Nonetheless his distaste for rotation brings difficult side effects: a number of his players have received relatively few minutes and his use of them during the Thursday-to-Sunday slog may have ramifications for the long-term evolution of his squad. Rob Holding, Takehiro Tomiyasu, Emile Smith Rowe and the soon out-of-contract Nelson will all be looking for evidence that they still have meaningful roles to play. The same goes for Kieran Tierney, the best and highest-profile of those who find themselves grasping for action. Tierney did not make the trip to Lisbon due to illness and misses a chance to show he can rival Oleksandr Zinchenko’s unique interpretation of the left-back role. He would walk into most Premier League teams and Newcastle are among those aware of the fact. Given he turns 26 in June, all parties may have a difficult decision to make this summer. “He understands the situation and needs to challenge the situation,” Arteta said. A similar quandary may apply to Smith Rowe, whose injuries have left him off the pace while Gabriel Martinelli, Martin Ødegaard and, recently, Leandro Trossard have excelled in roles he would happily occupy. He will be 23 soon; the time will come when he and Arteta have to convince each other Arsenal is the place where a richly promising career can blossom. “Sometimes it’s been difficult and players have to deserve to play the minutes,” he said. “Being fair in football is very difficult. You have to be really good at communicating your decisions to help players understand what you do, but all the time you have to think for the best of the team. We want everybody to feel important.” That is the challenge and, to be clear, Arteta has succeeded. Nelson, barely seen all season, would not have ripped into Bournemouth in such thrilling fashion had he felt like an outcast. But the scene presented to Arteta when he selects his Europa League sides reinforces the point that, when this season is complete, tough calls await regarding players who have contributed significantly to his and Arsenal’s rise. It would simply be the next stage of the squad’s development but, for now, there is a job to do with the players Arteta wants to satisfy. Jakub Kiwior, the January signing from Spezia, will probably make his debut against Sporting after waiting on the sidelines since his arrival. If Arteta wants to remember how tricky but necessary separations look, he need only glance at the figure of Héctor Bellerín lining up for the hosts. “Our priority is the two competitions,” he said, making at least some effort to pretend both fronts carry equal weight. He is far more relaxed on that score than a proportion of Arsenal’s support, but their season may be defined by how he handles the balancing act.