Diarra was expected to play again this season, but is already in action for the Hammers' development squad.
He wrote for whufc.com: "I am happy to now be doing my job, playing football, and my recovery has been amazingly quick. I am surprised, like everybody, but we've taken our time and worked hard together and my knee is steady and I can play.
"I played 90 minutes in the game on Tuesday against Gillingham and I think this was my last test. Now, I think I am available for the first team and hopefully I will train hard to have a chance to play with West Ham United.
"I am not feeling 100 per cent just yet, but my knee is feeling stable and stronger. With every training session I will get better and I am happy to be playing because it was eight hard weeks."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball