MotoGP champion Marc Marquez broke the titanium plate fixing the fracture in his right arm not while he was attempting an early comeback at Jerez, or doing gym work in the run-up to Brno, but 'opening a window'.

When Repsol Honda announced the surprise news that Marquez had been forced to undergo a second round of surgery on Monday, no mention was made of exactly when or how the previous plate (held by 12 screws) had been 'damaged' other than 'an accumulation of stress'.

But team manager Alberto Puig has now revealed that the metalwork, probably weakened by all the previous exertion, finally 'broke' while Marquez was opening a window at home.

"It was a domestic accident this time because he was trying to open a window and he suddenly felt a lot of pain," Puig said on the eve of this weekend's Czech Republic MotoGP. "Later we could check that the plate was broken.

"This was probably caused after all the stress that he had in the arm. But we went to Jerez because the doctors gave the okay to do it and they never informed us that the plate could have broken.

"If we had this info probably, he would not have gone to Jerez or Honda would not have given him the chance to ride."

Puig added: "Racing is a dangerous sport, but this thing didn’t happen in Jerez. It happened in his house. So if you look at it this way, no [he didn't take too much of a risk riding at Jerez].

"But it's true that when you have surgery and you stress some of the injured parts, clearly it's more stressful than doing nothing. But a professional sportsman is paid to perform and that's what he tried.

"The positive point is that it happened in his house and not at Brno on Austria on the bike, which could have had massive consequences if he had another crash. From now on we will have to keep checking the development of his fracture and only time will tell when he can return."

Surgery to replace the broken plate has forced Marquez to withdraw from this weekend's third round at Brno, while his participation in the following Red Bull Ring races is also in serious doubt.

Already 50-points behind double Jerez winner Fabio Quartararo and 40 from Maverick Vinales, Puig knows Marquez faces a massive task if he is to claim a seventh MotoGP crown during the already shortened season.

"You can never say never. It's never over, but clearly, it's more difficult and other guys have let's say an open 'window'… Guys that had no chance maybe now they have some chance.

"Mathematically it's more difficult [for Marc] but it's like this. Sometimes you win, sometimes you lose. In Marc's case normally he wins! Now that will be more difficult…"

Marquez broken his upper right arm in a highside at the season-opening Jerez race, underwent surgery the following Tuesday but then travelled back to the circuit where he was passed fit to ride in the second 'Andalucia' event.
After skipping Friday practice, Marquez returned on Saturday morning but withdrew at the start of qualifying after experiencing a sudden loss of strength in the arm.
It is not clear if the plate was damaged at that stage but it was definitely not broken, since Marquez was able to continue gym work at home over the following days:
HRC test rider Stefan Bradl will replace Marc Marquez, alongside younger brother Alex, this weekend.