Arsenal could have been sixth in the Premier League on Sunday and out of Europe this evening; instead they are in the top four and the quarterfinals, respectively, and the question now is how many further gears they can go through? A limping campaign has been transformed into two months -- and perhaps as many as 13 games -- of high-octane, do-or-die duels.

"It's given us very big confidence, against Manchester United on Sunday [when they won 2-0] and with this victory," Unai Emery said after Rennes were blown away by three unanswered goals. "This comeback was very difficult but our reaction was very good. Playing under pressure is good. Growing up under pressure, for each player, for the team, you feel difficult moments to give us our best performance."

Emery feels Arsenal have shown that, when the heat is on, they can deliver. Perhaps it is what this group of players, who have tended to switch off when the odds are overwhelmingly in their favour, requires. In the first 15 minutes of this second leg they were irresistible, showing no nerves in flying from the traps and quickly overhauling Rennes' two-goal advantage through Pierre-Emerick Aubameyang and Ainsley Maitland-Niles, deserving their lead even if the second goal owed much to an absent offside flag. After that they largely held Rennes, whose favoured tactic seemed to be attempting to draw Arsenal into a scrap, at arm's length before Aubameyang tapped in a third 18 minutes from time.

It was a convincing display, even if -- similarly to the win over United -- it was hardly a 90-minute exhibition of flowing football. Emery expressed mild disappointment that Arsenal had not shown more control with the ball but, more than anything, was delighted that over their past two games they have "been competitive."

They will have to maintain that level between now and May. Since the Europa League winners were rewarded with a Champions League spot, the question of priorities has become a popular one. It was asked of Manchester United when, in 2016-17, they juggled an unsuccessful top-four battle with a victorious Europa League campaign. Does one get in the way of the other? An argument can be made that Arsenal, whose squad is not necessarily stacked with reliable game-changers, might count the cost of flogging the same players on both fronts with two games a week from here on. But, having worked so hard to get into position at this stage of the season, can you really throw all your chips in one direction?

Emery stressed here that Arsenal will treat every assignment equally. Instinct says the combination of Manchester United and Chelsea, Arsenal's chief rivals for the top four, ultimately poses a greater and more sustained challenge than most of their possible paths to the Europa League trophy -- even if Maurizio Sarri's side are arguably their biggest obstacle to that. Emery, the Europa League specialist extraordinaire, noted the "big surprises" that knocked Inter Milan and Sevilla out of the tournament, and it was hard not to sense him smelling an opportunity.

"I said to my players, 'I am excited for this competition,'" he said. "It's a title. We can feel the possibility to win a title with a difficult moment like today."

While his team navigated the pressure points perfectly, Emery did too. With Rennes getting on top in the second half, he introduced Alex Iwobi and Henrikh Mkhitaryan, who instantly raised Arsenal's level. The latter supplied Sead Kolasinac with the pre-assist for the crucial third goal. Both players have been in and out of the side, but Emery, a master of knock-out football, knew exactly how they could wrest back control here.

It is one reason why Emery can legitimately envisage them walking out at the final in Baku on May 29. Arsenal have 18 days off now, which will partly be spent on a warm-weather break in Dubai before the squad splits for international duty. After that, their manager faces the balancing act that will define his first season in north London.

"[There are] exciting moments in front of us," he said. "A good possibility to do something."

For the first time in a while it genuinely feels like that for Arsenal; the pressure only gets greater from here, but perhaps at last that finds both team and head coach in their element.