Piquionne has joined Doncaster on an initial one month loan deal, that could be extended past that point.
Doncaster are currently desperate to move clear of relegation trouble.
He told the club’s official website: “I have been involved in scraps like this before at some of my previous clubs and I’m ready.
“In my head I’m a warrior and I will fight to keep Doncaster in the Championship.”
Doncaster boss Dean Saunders said: “He’s a player we’ve been after for a while and it’s a big signing for us.
“I want to thank West Ham as well for helping us with the wages otherwise we would never have been able to afford to sign him.”
