What made the 1-0 defeat harder to swallow was Hassan Maghoub's injury-time winner being set up by former Vélodrome favourite Mathieu Valbuena. After a decent first half, OM's level dropped in the second and they were made to pay right at the end, meaning their Group C task is already complicated and reviving memories of their last Champions League campaign in 2013-2014, when they finished with no points.

OM featured three survivors from 2013-2014 in their starting line-up and while captain Steve Mandanda showed up well, making some good saves, it was a much tougher night for Florian Thauvin and Dimitri Payet, who was returning from domestic suspension. Marseille created little and Dario Benedetto's form is a concern, with the Argentinean forward yet to get off the mark for the season.

No diamond, Gueye shows polish

Despite the success of the diamond midfield in the 3-1 win over Bordeaux last Saturday, coach André Villas-Boas opted to revert to a 4-3-3 with Payet and Thauvin flanking Benedetto and 21-year-old midfielder Pape Gueye selected ahead of the experienced Dutch international Kevin Strootman to fill in for the suspended Boubacar Kamara in defensive midfield.

Gueye was one of the few OM success stories on the night and Villas-Boas commented: "He played well and provided security. He has something extra when it comes to the defensive midfield role as he makes more runs and plays more passes in behind. I took him off because of fatigue and that was my choice, though he could have continued."

Villas-Boas and OM face a challenging Matchday 2 home game against Manchester City, who came from behind to beat Porto 3-1 on Wednesday evening. OM were shown the way by Olympique Lyonnais, who saw off Pep Guardiola's side in the quarter-finals in Lisbon a couple of months ago.

Tactical tweak for City?

OL played with three centre-halves against City and Villas-Boas dropped a strong hint of a change to OM's tactics for the crunch fixture at Orange Vélodrome. The Portuguese said: "We're going to put something different into place against City, because of the strength of their team and their collective characteristics."

OM struggled to get pace into their attacks in Piraeus and lacked fluency, with Villas-Boas spending a fair amount of time shouting at midfielders Valentin Rongier and Morgan Sanson about their positioning. Payet and Thauvin are such key players for Marseille that it is hard to see them dropping out against City, though Benedetto must fear for his place with 18-year-old Luis Henrique desperate to make his mark. Creative midfielder Michael Cuisance will also want to press his claims for a starting place.

Villas-Boas: "I protect my players"

Quizzed about his team's shortcomings at the highest level, Villas-Boas riposted: "You know it's not worth asking such questions of me, I protect my players. It's me who decides the organisation of the team. I changed my three forwards, for example, and I have no criticism of them, I was chasing the win. If my players aren't capable of performing at the top level then I am responsible for that, and it's down to me to get them up to Champions League standard, to make them improve still further."