LONDON (AFP) - Mamadou Sakho, who could make his Liverpool debut at Swansea City on Monday, hopes to repair a career that began to unravel on a wintry night in north-west France in January 2012.
Sporting the captain's armband for Paris Saint-Germain, Sakho conceded a penalty with a rash sliding challenge on an opposition forward in the 71st minute of a French Cup tie at Lorient's Stade du Moustoir.
Worse, PSG were playing Saint-Colomban Locmine, an amateur team from the French fifth tier, who promptly equalised from the resulting penalty.
Worse still, Sakho was making his first appearance under new coach Carlo Ancelotti, who had succeeded Antoine Kombouare just 10 days earlier.
Ancelotti took Sakho off almost immediately and although Diego Lugano spared PSG's blushes with an injury-time winner, it marked the beginning of a painful slide into obscurity for his younger team-mate.
Initially, Ancelotti persevered with Sakho but that April he lost his place in the side, telling sports daily L'Equipe he found his situation "maddening and frustrating".
He was omitted from the France squad for Euro 2012 and the arrival of Thiago Silva at PSG from AC Milan weeks later only compounded matters.
Although he made 24 Ligue 1 starts last season, he watched many key games - including both legs of the Champions League quarter-final against Barcelona - from the bench.
When another Brazilian centre-back, Marquinhos signed from Roma in July, the writing was on the wall and yet, just two years previously, Sakho had had the world at his feet.
Aged 21, he was voted the best young player in Ligue 1 by his peers and included in the team of the season for the 2010-11 campaign.
PSG team-mate Clement Chantome said he was "the best defender in the French championship". An anonymous opponent told L'Equipe: "When he hits the ball with his head, it makes such a sound you think it's going to explode." Prior to the takeover of PSG by Qatar Sports Investments in the summer of 2011, Sakho's career had pursued a steady upward trajectory from the moment he joined the club at the age of 12.
The fifth of seven children raised by Senegalese parents in a working-class district of northern Paris, Sakho lost his father a year after joining PSG and says that, as a result, a career in football became "an obligation".
A physically precocious, naturally assertive centre-back, he made his PSG debut at the age of 17 and was promptly made captain by then-manager Paul Le Guen, setting a new Ligue 1 record.
Many saw in Sakho the potential for a life-long affiliation with PSG in the manner of AC Milan great Paolo Maldini, whose former club were among several starry names to show an interest in the hulking number three as his stock continued to rise.
Ironically, however, it was at the hand of Maldini's one-time Milan team-mate Ancelotti that things began to fall apart for Sakho, who was judged too impetuous by the former Chelsea coach.
Sakho will not want for visibility at Liverpool, though, and by proving himself at Anfield he will hope to resurrect an international career that slipped into decline as his star waned in Paris.
He will have more than half an eye on winning a place in France's squad for the World Cup, should they qualify, and the move to England will also enable him to observe some of his idols at closer quarters.
"Some of my team-mates were champions of France, so I'm interested by the teams they played in and the mentality of the players," he said in May 2011.
"For example, I asked Claude Makelele how John Terry thought, how he worked. Then I compare myself, see what I'm missing." If all goes to plan for Sakho, it will be PSG who see what they are missing.