Strikeforce lightweight Josh Thomson has been forced out of his upcoming fight with Maximo Blanco on Sep. 10, 2011, because of an unspecified foot injury, which is said to have occurred this past week during the fighter's training camp. 

It's unclear at this time how long "Punk" will be out of action, as well as whether or not a replacement opponent for Blanco -- a Sengoku standout who was set to make his highly-anticipated promotion debut -- will be secured in time for the event at the U.S. Bank Arena in Cincinnati, Ohio.

With less than three weeks until fight night, it might be a tall order.

This is more bad news for Thomson (18-4), a former lightweight champion, who was able to string together consecutive wins over Pat Healy (Strikeforce: "Fedor vs. Werdum") and Gesias Cavalcante (Strikeforce: "Diaz vs. Noons 2") before Japanese "Crusher" Tatsuya Kawajiri battered him en route to a unanimous decision loss at K-1: "Dynamite!! Power of Courage 2010" last December.

It was just his second loss since 2006. And he's itching to get back into the promotion's lightweight title hunt. He'll now have to wait a little while longer.

Strikeforce: "Barnett vs. Kharitonov" features the second leg of the promotions heavyweight grand prix tournament with Josh Barnett battling Russian bomber Sergei Kharitonov and Daniel Cormier locking horns with Antonio Silva.

In addition to the two heavyweight grand prix bouts, middleweight champion Ronaldo Souza will defend his title against the returning Luke Rockhold, while other intriguing match ups pitting Muhammed Lawal vs. Roger Gracie and Mike Kyle vs. Gegard Mousasi will also be featured on the card.