After breaking his right arm at the 2020 Jerez opener, Marquez made an ill-fated attempt to return the following weekend before being forced to withdraw.

Further arm complications due to plate damage and infection meant Marquez wasn't seen in MotoGP again until Portimao, in April of 2021.

But just when the eight-time world champion was getting the better of his arm and shoulder issues, he was struck by diplopia after an enduro training accident in October, forcing him out of the final two rounds.

Sidelined until February's Sepang test, a huge highside in warm-up at Mandalika on March 20 then triggered another dose of double-vision.

Fortunately, the recovery time was quicker on this occasion, allowing Marquez to ride out of his pit garage in Austin just under three-weeks after the Indonesian accident.

But having gone through so many injury setbacks, and with the huge Mandalika accident and ever-present risk of more diplopia not doubt on his mind, Marquez spent Friday's sessions rebuilding confidence on the all-new 2022 machine.

"Today was difficult to start, but I tried to start in an aggressive way. It was the best way to forget the past, to forget the crash and the last two weeks," Marquez said. "I tried to relax, to ride well and we didn’t try to touch the bike.

"Tomorrow we will start to work for the GP, but today was ‘my day’ and with the team we just concentrated on me and to believe again on the bike."

Nonetheless, Marquez featured at the top of the timesheets on his way to fifth in FP1, then cut 1.5s from his best time to claim sixth place in FP2.

But it wasn’t exactly a surprise. With seven wins from eight COTA appearances, only Sachsenring ranks as a more successful venue for Marquez, who made clear he is 'here to compete'.

If my eyes are not OK then you cannot ride fast. I said to the team 'do not ask, if I have some problem I will say to you…' I came to Austin to compete, not to make some laps.

"To compete well you need to work like always: on the set-up and all these things."

The set-up Marquez used on Friday had been "the one I crashed with in Indonesia. It was the base we used in pre-season and raced in Qatar. There was no need to change so we started from that and then tomorrow we will try to find a good way.

"Already we found some problems and it is time to understand how to improve. In this circuit where I have a good feeling it is more important because then you are sensitive to try the things.

"The front of this bike is one of the weak points for my riding style. It is where I am struggling more," Marquez confirmed. "Still today I had some warnings that I did not understand well so I know the team have some ideas and tomorrow we will go in that way.

"I believe, of course, in the team, and we will understand. Also Honda is working to improve the front character of the chassis area for the next races."

The unusual Friday approach also extended to how Marquez managed his physical effort.

"I was riding in 2m ’06 and then just pushed for single [fast] laps. It’s the only way to survive the whole weekend," he said. "It is true that tomorrow in the afternoon I have to try and work for the race pace because it is different to ride very slow and then push for a single lap.

"But it’s the only way I have to finish the weekend in a good way [physically].

"For that reason, Friday was about trying to understand and to have the feedback. Tomorrow, I need to push and it will be difficult to be in QP2 directly because all the Ducatis are very strong and fast in a single lap.

"Already last year was difficult [in qualifying]. I was on the front row but it was difficult over a single lap, for some reason Ducati will be so fast. Qualifying is not our strong point but we try to be in the first two front rows."

One of those fast Ducatis, title runner-up Francesco Bagnaia, repaid the compliment: "The Ducatis are strong. Also Suzuki. Aprilia with Vinales. And Marc for sure. It’s his track so he will be strong."

Pol Espargaro in 'a lot of pain'

While Marquez was making his latest injury comeback, team-mate Pol Espargaro suffered an early fall in the morning session, then was struck down by illness ahead of the afternoon.

“Today was a really tough day, I am not feeling well and I have no power because I have a lot of pain and upset in my stomach," said Espargaro, who dropped from sixth in the morning to twelfth in the afternoon.

"In the morning it was OK but for the afternoon session I was finished, I tried sleeping between sessions to help. The bike is performing well and there’s a lot of potential, but I have no strength.

"This is maybe one of the most difficult tracks to have a problem like this at because it is so physical. The plan is to head straight to the hotel and rest as much as possible before tomorrow.

"We need to put together one fast lap for Qualifying but there are many people who will be strong over a lap.”

The Ducatis of Johann Zarco and Jack Miller topped the Friday timesheets in Texas.