With qualification to the knockout phase of the Champions League secure even in defeat, there will be a temptation for Arsenal to dismiss this result as a meaningless irrelevance.
Climbing the Premier League, after all, ought to be the priority just now, especially with a match of such importance looming at the Emirates on Saturday against West Brom. The argument that this loss carries little importance could gather further momentum when it is considered that Arsenal fielded what amounted to a reserve team. Yet, in its own way, this was just as depressing as Saturday's performance against Swansea City.
Not in the manner of the 2-1 defeat but the fact that, where once Wenger (right) had a hungry young group of emerging talent to fall back on, the cupboard now looks worryingly bare.
Marouane Chamakh, who has started only one game this season, was given a full 90 minutes but never looked like scoring his first Champions league goal in nearly two years.
Similarly, Andrey Arshavin produced only the most sporadic flash of the brilliance he once regularly produced. Tomas Rosicky, who scored Arsenal's goal and was clearly their best player, provided the only reason for hope.
Lukas Podolski, Santi Cazorla, Theo Walcott, Olivier Giroud, Bacary Sagna, Kieran Gibbs, Per Mertesacker, Andre Santos and Jack Wilshere were all rested and spared the three-hour flight to Athens, but there was still no shortage of experience in the Arsenal team.
Nine of those who started are full internationals, with only Jernade Meade, the 20-year-old left-back, making his full first-team debut.
Indeed, with so many of Arsenal's usual team so short of form, the most intriguing part of Wenger's selection was the opportunity he presented to more peripheral players.
Sebastien Squillaci, once a France international centre-back, was being seen in an Arsenal shirt for the first time this season and had not played in the Champions League since the corresponding fixture against Olympiakos last year when Arsenal had also already qualified for the knockouts. Alongside Thomas Vermaelen, he looked assured enough in the opening minutes as Arsenal quickly established control of possession.
Rosicky was looking especially comfortable in possession and Arsenal quickly created four decent chances. Gervinho, who had moved to the left in order to complement Chamakh up front, shot narrowly wide.
Alex Oxlade-Chamberlain found a target for his cross moments later but, with Chamakh having sensibly cushioned his header back across the six-yard box, Aaron Ramsey connected only with fresh air with the goal at his mercy.
Just as Arsenal had one eye on more important challenges, there was also a sense that Olympiakos, despite a 10-point cushion in the Greek league, were thinking about their weekend fixture against Panathinaikos. Several key players had also been rested but, backed by fervent home support, they came strongly back into the game.
Particular pressure was being exerted on Arsenal's two inexperienced full-backs and, although Meade was coping admirably well on his debut, gaps were appearing behind Carl Jenkinson. Arsenal also looked vulnerable from set-pieces, with Rosicky displaying rare defensive qualities to clear a Pablo Contreras header off the line from a corner.
Chances, though, were still being created at both ends and a goal of real quality was to give Arsenal their half-time lead. Gervinho had been at his erratic worst for fully 38 minutes, wasting a succession of good positions and running down a series of blind alleys before darting down the right of the Olympiakos penalty area. With several defenders committed, he then slipped a pass across goal for Rosicky, who complemented his perfectly timed run with an accurate side-foot finish.
It was to be his last action of the night, with Rosicky, who was making making his first start following Achilles surgery, replaced at the interval by Arshavin. It was not quite a straight swap, however, with Arshavin asked to play down the left and Oxlade-Chamberlain moving the centre.
Arshavin, though, had an immediate chance to extend Arsenal's lead but was just unable to control his header. The Russian then forced an excellent one-handed save from Roy Carroll with a powerful volley.
Olympiakos continued to threaten and Paulo Machado headed wide following a combination of Wojciech Szczesny's hand and the post. Szczesny was adamant that he had not touched the ball and Arsenal's complaints were compounded when Ioannis Maniatis finished from close range from the resulting corner after Ramsey had failed to clear.
Olympiakos then really should have taken the lead, with Rafik Djebbour somehow directing a header wide of the goal from just three yards out.
Arsenal were wilting and finally succumbed to another deserved defeat when Kostas Mitroglou curled past Szczesny from the edge of the penalty area. (© Daily Telegraph, London)