Luckily, we do have a bit more information now available courtesy of Martijn de Jong. The Golden Glory trainer has publicly addressed the issue in an interview with Dutch site Mixfight.nl. It's not a very lengthy interview, but provides good insight, including more on why Overeem dropped out of the Strikeforce Grand Prix, and why he took the October fight for United Glory. Regarding the GP, de Jong says (translated):
Alistair really wanted to participate and win the Strikeforce tournament. Its a prestigious tournament and he was very happy to be part of it. He also had the best papers to win this tournament according to many fans and off course we believed it as well. The problem is that he is injured and not able to be ready and fight on september 10th in the semi finals. Don't forget that Big Foot Silva is a very dangerous fighter so Alistair needs to be 100%. Also we have doctors statements to proof he is injured and can't be ready for September 10th.
He also directs fans to watch the latest episode of the online documentary The Reem, which, as we noted, reveals Overeem to be suffering from a previously undisclosed rib injury.
Finally, de Jong mentions being surprised at Overeem's cut from the company, and argues that Strikeforce made the decision to remove him from the tournament. This goes against Dana White's statement that it was Overeem's choice, and that they wanted him to stay in.
Read the full interview here.
A number of questions still remain regarding this situation. Will Overeem's removal from Strikeforce keep him out of the UFC? Will Strikeforce crown a new Heavyweight champion? What are the details surrounding this rib injury, and will that keep Overeem off the October card? And with the recent purchase of K-1, will we see the reigning K-1 Grand Prix champion making a return to kickboxing?