Conor McGregor had 'multiple stress fractures' in shin ahead of defeat to Dustin Poirier

Irishman suffered a broken leg in UFC 264 bout and has undergone surgery in California

Conor McGregor is carried off on a stretcher following an injury suffered against Dustin Poirier during UFC 264 at T-Mobile Arena in Las Vegas.

Conor McGregor after suffering an injury.

Conor McGregor moves in for a hit against Dustin Poirier during UFC 264.

Conor McGregor lands a hit against Dustin Poirier.

Conor McGregor following his ankle injury.

Former US President Donald Trump attends UFC 264.

Conor McGregor has said he had "multiple stress fractures" to his shinbone heading into his bout with Dustin Poirier at UFC 264 - where a broken leg resulted in a defeat for the Irishman.

McGregor, 33, was aiming to settle the trilogy with Poirier having lost to the American at UFC 257 in Abu Dhabi in January, but the fight ended at the end of the first round when the former champion rolled his ankle and broke the lower tibia in his left shin. The fight was called off by the doctors and the victory awarded to 32-year-old Poirier.

McGregor underwent surgery in California and on Thursday posted a video to his Instagram account to provide an update of his recovery and to thank the fans for their support. He also revealed that he carried shin injuries into the bout in Las Vegas and there were discussions to delay the fight.

"Everyone keeps asking me at what point did the leg break," McGregor said as he cruised around in a motor scooter with his leg elevated in a cast. "Ask [UFC president] Dana White, ask the UFC, ask Dr [Jeffrey] Davidson, the head doctor of the UFC. They knew ... I had stress fractures on my leg going into that cage.

"There was debate about pulling the thing out because I was sparring with no shin pads and I kicked the knee a few times, so I had multiple stress fractures in the shin bone above the ankle.

"I even did a lot of training sessions when the ankle was sore, I still wouldn't stop training. I used to train on my back and that's how I developed those ground and pound shots from the back.

"It was a skill I developed because of the damaged leg and I had to adjust my training."

Facing a long road to recovery, McGregor - who turned 33 on Wednesday - said he is "motivated to keep going".

"When I came out of surgery I was feeling euphoric," he said. "It was a great job that was done. I was thinking 'yes, this is going to be easy, I can do this no problem'. Then I hit a wall and I was thinking ... 'I'm in a lot of pain, I'm going to be like this for a while ... it's going to be a bit of time'. I know there is going to be ups and downs on this journey and I'm a bit more accepting of it and I'm motivated to keep going."

McGregor revealed that he has had a titanium rod inserted into his leg "from the knee to the ankle" and he joked: "I'm like Arnie (Schwarzenegger) in Terminator 2."