The six-time world champion, who finished Friday’s FP2 fourth-fastest, went down at Turn 2 in FP1 before crashing at Turn 1 in FP2.
But Marquez put the crashes down to his willingness to take risks, and said he will do the same on Saturday for FP3 and qualifying even if it means a third crash.
The Honda rider explained that “every race I want to see if I have this fire inside me, and I have,” adding that he had been able to ride in a completely normal way on Friday for the first time amid his continuing recovery from arm surgery.
He said: “The grip level was good, especially when you come from Malaysia. Malaysia was very poor for us.
“You arrive here and the grip level was good, then with a high grip level our bike is working better.
“Even like this today, I had some problems and I didn’t feel the way to push. But it’s the last race, it’s a Spanish GP, and I decide to take a risk.
“I take a risk today, I crashed twice, I will take a risk tomorrow. Maybe I crash again, I don’t know, but I will take a risk on Sunday the same, because I want to finish in a good way.
“But in the end, I have what I have, and then I will try, but I have what I have and I need to wait until Tuesday [in the post-event test] to do I hope another step.”
Asked whether he had struggled more than he expected at Circuit Ricardo Tormo, Marquez added: “No, I struggle what I expected.
“I said yesterday it will be between Australia and Malaysia, and we are at the moment between Australia and Malaysia, we are fourth.
“We are there. I know that tomorrow with a single lap for the fast lap it will be difficult even to be in the front two rows, maybe the target is to be in the third row. But we will see.
“As I say, I will take risks because I want to do something more on my side. Then the result, maybe it’s worse or the same than Malaysia or Australia.
“But on my side, during all the races, I was fast but always trying to control everything.
“But every race I want to see if I have this fire inside me, and I have. Today I showed to myself if I want, I can push, but I have what I have and I can do what I can do, no more.”
Despite a strong result on Friday, Marquez had an audibly sore throat, and told journalists he was taking medication after waking up feeling unwell.
He said: “I’m destroyed. I’m happy, because the target of my comeback was improve my right arm, and we improve a lot.
“Today I ride normal way and it was a long time that I don’t ride like a normal way, so for that reason I push more and I crash more.
“But I was riding very good, but I get up and I was sick. I’m taking medicines and yeah, tomorrow I hope to feel better and Sunday better but you never know.”
