The midfielder requested a transfer last January after criticising Sam Allardyce's team selections, and was sent out on loan, but now wants to succeed in the Premier League
Diarra only made three Premier League appearances for the Hammers last season before requesting a transfer and heading out on loan to Ligue 1 outfit Rennes.
However, the 32-year-old is hoping he can take his encouraging end-of-season form in France into the new season, and is prepared to earn first-team opportunities.
"I want to fight this season with West Ham," Diarra told the club's official website. "I'll give 100 per cent in training and I'll wait for my chance.
"I want to give my best for West Ham and we'll see. I'm ready to play in the Premier League now.
"Pre-season has gone well. We work hard every day, and we've only lost one game so it has been a good start for us."
Diarra believes a lack of a break following Euro 2012 ahead of his debut campaign in England may have been a reason for his slow start to life in the Premier League, having suffered a thigh strain soon into West Ham career.
"It is a very different pre-season for me," the Frenchman added. "It's a big chance for a player to be fit and for me it is much better being involved from the start this year. I missed it last season, so it was hard to come back.
"That was difficult, but now I have this chance to start with the squad, so that is good for me. I feel good at the moment. I can run, and move, but it's not 100 per cent yet. There are three weeks left to get ready for the Premier League and I want to fight this season with West Ham."