UFC heavyweight Stefan Struve reportedly fainted backstage at UFC 175 tonight in Las Vegas, causing the cancellation of his scheduled bout.

Struve, who was to be making his return to MMA after a year off due to health issues, was described as having heart palpitations and suffering what was termed a “near-fainting spell” by Dr. Jeffrey Davidson, a medical consultant for the UFC.

The fighter, a 26 year old from the Netherlands, is said to have recovered fully. But his scheduled bout with Matt Mitrione was called off — and he was taken in to medical supervision as a precautionary measure.

Struve last fought in March 2013: a knockout loss to Mark Hunt. Later in the year, he was diagnosed with a leaking aortic valve and an enlarged heart. He was cleared to fight again this year, but tonight’s events place his future in question again.

UFC commentator Mike Goldberg announced the cancellation on-air during the pay-per-view broadcast. He added, “We wish Stefan all the best.”

Update: After the event, Dana White told the media that Struve is doing “great;” but added he needs to consider his health, adding: “I’m not sure if he should fight again.”

Struve himself offered this via his Twitter account: