Strikeforce heavyweight champion Alistair Overeem has been removed from the promotion’s heavyweight grand prix after declining a September 10 date for his semifinal matchup with Antonio “Bigfoot” Silva.

Undefeated prospect Daniel Cormier will replace Overeem and face Silva at the Showtime-televised event, according to Tatame.

The move came just hours after Overeem announced that Zuffa threatened to pull him from the tournament if he didn’t fight in September instead of a planned October return.

The September 10 Strikeforce fight card is also expected to feature the second semifinal between Josh Barnett and Sergei Kharitonov as well as middleweight champ Ronaldo “Jacare” Souza vs. Luke Rockhold, which was confirmed with three other bouts earlier today.

More.

White: Overeem still under contract with Strikeforce, will fight again when toe heals

While Alistair Overeem (35-11 MMA, 3-0 SF) will no longer compete in Strikeforce's heavyweight grand prix, he will fight again under the promotion's banner.

MMAjunkie.com (www.mmajunkie.com) today confirmed with UFC president Dana White that the Strikeforce heavyweight champion is still under contract with the promotion and will return to action when a nagging toe injury is healed.

"Sept. 10 was the date Showtime wants us to go, so it's the date we've got to go," White said. "It's unfortunate that Alistair is unavailable, but situations like this are why there are alternates in the tournament."

In addition to his duties as UFC boss, White is also a minority owner of Zuffa, LLC, the parent company of the UFC that recently acquired Strikeforce, as well.

Overeem today revealed on MMA Fighting's "The MMA Hour" that the promotion requested he return to action against Antonio "Bigfoot" Silva (16-2 MMA, 3-1 SF) on Sept. 10. However, the Dutch striker said he asked for more time and preferred an October booking.

With the company planning for a September event to host the promotion's heavyweight grand prix semifinal bouts, some obvious tension was built. Overeem said the company threatened his release even before today's official announcement.

"What's going to happen next, I don't know," Overeem told MMA Fighting. "I've had some threats of cutting me out of the tournament if I don't participate. I don't know if they're going to do it."

Overeem's publicly stated position was that the Sept. 10 date was too soon to return to action and that he needed time for a broken toe to heal.

However, MMAjunkie.com spoke with several sources who suggested Overeem may be posturing in hopes of better terms on a new contract. It's believed his current Strikeforce deal has just one fight remaining. However, White declined to comment on any potential ongoing negotiations.

According to the UFC boss, it's simple. Overeem is hurt, but the show must go on.

"Overeem is under contract, and when his pinky toe heals up, we'll get him another fight," White said.

Strikeforce brass today officially announced it will conduct an event on Sept. 10. However a location and venue have yet to be revealed.