Houllier bought Traoré from second division Laval despite competition from Paris St Germain, AC Milan, Parma and Lazio. Traoré seemed nervous enough when his big chance arrived at the start of the 2000/01 season when he was put in the unfamiliar role of left-back. He was loaned to France the following season and gained valuable experience with Lens and almost won the French championship. Traoré returned a stronger character and found his feet when he was moved to his natural centre-half position when Stephane Henchoz got injured in the 2002/03 season. Traoré was out of favour with Houllier which proved to be his last campaign as boss, in 2003/04. Traoré welcomed a change at the top: "A lot of the French players didn't have a chance to play and express themselves. We had to work twice as hard to play. In the end, I didn't trust him anymore. I was upset. So many times I knocked on his door saying I wanted to leave the club. It was frustrating because I didn't play. And nothing changed. If he would have stayed then I would not be at Liverpool anymore." Benítez showed a lot of faith in Traoré in his inaugural season in English football using him as a left-back opting for the centre-half pairing of Sami Hyypia and Jamie Carragher. On 18 January 2005 Traoré scored a disastrous own goal when Burnley eliminated Liverpool in the third round of the FA Cup but credit to him he didn't lose his focus and will forever be a part of Liverpool's victorious team in Istanbul where he played the whole 120 minutes. Traoré was used less by Benítez the following season as it was painfully clear he wasn't up to the high standard required at Liverpool.

During the summer of 2006, Traoré was sold to Charlton Athletic. He was sent off on his debut against West Ham on the opening day of the 2006/07 season. He committed an outrageous foul on Jermaine Pennant when Liverpool visited the Valley in the middle of December, a challenge that saw a penalty awarded against him, which Alonso duly scored. Shortly afterwards, Traoré was sold to Portsmouth but made only ten league appearances between his debut on 13 January 2007 and the end of the season. Traoré moved to Rennes on loan in the following season and the French club seemed keen to make the deal permanent but were unable to reach an agreement with Portsmouth. Championship club Birmingham City was his next stop in February 2009. Although Birmingham were promoted back to the Premier League at the end of the 2008/09 season, Traoré could hardly claim any credit for that as he appeared on only three occasions. In June 2009 Traoré eventually left Portsmouth for Monaco, whose manager, Guy Lacombe, had been in charge at Rennes when Traoré had a loan spell there in 2008. He played in 29 league and 3 cup matches for Monaco in 2009/10 and his career seemed resurrected. However, Traoré only played in seven Ligue 1 matches for Monaco during 2010/11 as he was unavailable in the second part of the season because of a cruciate ligament rupture. Traoré signed a one-year contract with Marseille in August 2011 but only made 14 first-team appearances and left the club when the contract expired in the summer of 2012. In February 2013 Traoré joined Seattle Sounders in the MLS.

Traoré played in fifteen first-team matches for Seattle between early-March and early-June 2013. Seattle Sounders finished the 2013 season fourth in the Western Conference division and sixth in the overall table. The defender was still playing fairly regular for the club from Washington state as the 2014 season got under way. At the end of that season he retired from playing and took on a coaching role at the club.