Having only recently been cleared to start gym work, following his fourth right-arm operation, Marquez admitted the raw power of a MotoGP machine came as a shock for even the six-time premier-class champion.

“I only started in the gym two weeks ago, did two days on a [road] bike and then straight to MotoGP! So the timing was quite tight and there is still a long way to go, but I feel good,” Marquez said.

“I didn’t enjoy the first run because these bikes are too fast!

"But from that point on I started to enjoy it a bit more. Still, after 100 days [away] you are riding mostly by instinct."

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“The bone is 100% fixed,” he explained. “So with the bone I feel perfect, it’s the muscles. On the fracture area, I don't feel any pain. But it's more all the elbow and especially on the shoulder and on the back.”

“Honestly speaking, I was suffering [physically] more than enjoying this first day, but it's sometimes like that even if you do a normal [winter training] and then arrive for the first day in Qatar.

“These bikes are so powerful. You can be very fit but [on] the bike is different.

“Today everybody was super-fast because they are coming from a race weekend. I just concentrated on the way to ride the bike and especially my position on the bike.

“And it was not bad. So tomorrow we will try to do another step.”

The Spaniard completed 39 laps during the morning session, the best of which put him 17th fastest on the timesheets but only 0.864s from fastest man Aleix Espargaro (Aprilia).

“The lap time was not bad, but it was not the most important,” Marquez said. “The most important thing is that my body, my arm, accepted these 39 laps in a good way.

“It’s true that I was doing very short runs. And I was touching my shoulder, the arm, [in the pits] because the muscles were working in a different way for one year and a half.”

That was the length of time Marquez’s right humerus was rotated 34 degrees out of line, causing the 29-year-old pain and mobility problems before being corrected during surgery in early June.

“Now all the muscles are working in the proper way, but they are not ready to hold all this torque, all this power of the MotoGP bike.”

Marquez’s two-wheel comeback on the CBR600 had taught him that the day after riding might be most problematic physically.

For that reason, the team insisted on Marquez sticking to the 40-lap limit in order to save his muscles for Wednesday’s final day.

“Today the plan was 40 laps. I did 39 and stopped at midday. We did exactly the plan that we [made],” Marquez explained.

“I asked, ‘maybe in the afternoon we can ride?’ But they stopped me because today is the first day and we [will] try to ride tomorrow.

“Now I will have some special work with ice and physio, just to try to control the recovery of the muscles. The pain is not a lot, but the recovery of the muscles is important.

“And tomorrow if I have a good feeling [the plan] is to continue riding and if I can do more laps than today, I will.”

Marquez tried a new Honda fairing

On the technical side, with Marquez yet to use his one allowed in-season fairing update, the Spaniard tried some new aerodynamic updates.

“Today and even tomorrow I will try to concentrate on the aerodynamic package because still I have one chance to homologate [a new fairing] on my bike. And for that reason we are trying to understand,” he said.

“I felt a bit, but tomorrow is time to reconfirm because, after 100 days, like I say, you can be fast, but you don't have the special feeling with the bike. You cannot understand in a proper way.

“But the good thing is that my comments were exactly the same as Bradl. So this means that we are in the same direction.”

‘Tomorrow will be important’

The big question now, especially in terms of a potential race comeback next time at Aragon, is how Marquez’s body responds to the stress of riding a MotoGP bike over the next few days.

“If today was a race distance, it'd be impossible to finish. I could do 10 laps in a row, but 27… I’m far [from being able] to do,” he said.

“It will be important to ride tomorrow and then understand on Thursday, Friday, how my body and the arm accepted [the physical work] and if I feel I’ve made a step forward - or maybe sometimes, after a big effort, you go one step back, because you start to feel some pain.”

Bradl tests Kalex swingarm

Meanwhile, as rumoured, HRC test rider Stefan Bradl was spotted on track using a new aluminium (rather than the usual carbon fibre) swingarm built by Kalex.