Diomede won the World Cup with France in 1998, though his input wasn't crucial as he didn't feature from the quarter-finals onwards, the fact remains he is only of a select few who have been on Liverpool's books who can call themselves world champions. Diomede, who is of Guadeloupean descent, arrived at Anfield with decent credentials after eight years at Auxerre, in June 2000. He had made a valid contribution to Auxerre's league and cup double in the 1995/96 season, but after playing 175 league games and scoring 30 goals he had fallen out with the management and wanted a fresh challenge. Diomede only made four starts for Liverpool in the treble 2000/01 season and the only thing he did of note was to score with a wonderful overhead kick against Sunderland in his second game, but the ball was judged not to have crossed the line which on replay was shown to be a wrong decision. He was loaned out to Ajaccio in his final season and impressed them enough to snap him up when his contract at Anfield expired in 2003.

The left-winger was dismayed when the French 2003 Rugby World Cup squad named a live cockerel, its lucky mascot, after him: "At first I thought it was a joke," Diomede said not all appreciating this "honour". "My first reaction was that before using someone's name they should ask. There aren't many Diomede's in the world. I've got a sense of humour, but I would have liked to have been told about it. It's less funny when you're the one concerned. I just hope all this won't disturb my family too much." Diomede, the cockerel that is, was flown home to France for medical tests early on in the World Cup as his crest was turning from red to black. Much like his namesake's career at Liverpool, he had faded after a promising appearance.

After Diomede's contract at Ajaccio came to an end he was invited on a week's trial to Bryan Robson's West Brom, who were on the bottom of the Premiership, in January 2005: 'It is not as if Bernard is old,' Robson said. 'He is at the peak of his career and we are going to look at him for the week. He is a player who was bought by Liverpool for £3 million a few years ago. He is now a free agent. Early impressions are encouraging. While he was at Liverpool, I saw him play a couple of times but he never really had a good chance there." Robson didn't offer Diomede a contract and he later joined Ligue 2 Creiteil and then Clermont Foot in the Championnat National, the French third division. "How the mighty have fallen" is an old idiom that comes to mind. In January 2008 Diomede retired after being without a club for the past 18 months.

Diomede has since gone on to establish a football academy at La Salle Sant Nicholas in Issy-les-Moulineaux, south of Paris.