Nate Marquardt hasn’t been seen since he failed a pre-fight medical for his main event bout at UFC On Versus 4 last night and was then promptly fired by the UFC.

Today the 32 year-old did however surface briefly to issue an apologetic message via his Twitter account, though he steered clear of giving any new details on the situation.

“I’m sorry to all my fans and the UFC for not passing the medicals for tonight’s fight. I’m heart broken I couldn’t fight, but I will b back.”

So mystery remains over the reason that he is now no longer employed by the UFC where he has been gainfully employed for the past six years.

Fans are desperate answers, but so far they have been remarkably hard to come by and there’s no guarantee exactly when they will become available, even as the event itself looms this evening in Pittsburgh.

The Pennslyvania Athletic Commission will hold a press conference at 4pm Eastern Time, but the word is that this may be very much a formality and will reveal little in the way of detail regarding Marquardt’s failed medical which prevented him from competing this evening.

That leaves two main other avenues open to get answers – firstly Marquardt’s management team Alchemist MMA have stated that they will release a statement later today, while Dana White is expected to be a special guest on the Versus pre-fight show with Ariel Helwani at 8pm ET.

Rest assured we’ll endevour to bring you the latest news on the situation as soon as it breaks.

Update: According to Marquardt’s management the fighter himself will be addressing all the issues involved in this matter on Tuesday.