Under Sam Allardyce, Diarra had two seasons at West Ham, although half of the second of those was spent on loan at Rennes.
Diarra made just six Premier League appearances for West Ham, before being released at the end of the 2013-14 campaign.
Now at Charlton Athletic, Diarra has spoken of his unhappy time at Upton Park.
"My first experience in England was frustrating because I didn't play many games at West Ham," he told Charlton's matchday programme.
"I did well in training but it just wasn't football. They played a lot of long balls but for me that is too easy. I've always played hard stuff. I like to get into position with pressure.
"If you are not first choice with the manager you have to wait for injuries or suspensions to get your chance and even then I didn't get it. But that's in the past for me now.
"I didn't learn anything during my two years at West Ham. I've learned more in the last month at Charlton because we try to play football. We try to keep possession and win every game and for me that is football.
"It's about ambition. I'm a competitive guy and I need to win every game, not only some games."
