GP2 runner-up Bruno Senna remains upbeat about his chances of graduating to Formula One next year, despite the news of Honda's withdrawal.
Senna tested for the Japanese manufacturer at Barcelona last month, and was in the running to partner Jenson Button next year.
However, Honda's announcement that it will withdraw from F1 with immediate effect, and close its Brackley-based team unless a buyer is found, means his favoured option is now closed.
"It's a bit of a shock, we didn't know the situation was that serious," Senna told autosport.com.
"They told us the news yesterday [Thursday] so obviously it's a difficult situation for them, but at the same time I have to thank Honda for giving me the first opportunity to test a Formula One car and I now know I'm ready for that challenge.
"It was a great showcase for me to go there and show what I can do in an F1 car."
Despite Honda's withdrawal as a works force, Senna says other F1 options remain open to him.
"It's not put us in a situation where we are completely out of options," he said. "We haven't given up on racing in Formula One next year. We are working quite hard on other opportunities. It's time to sit back a bit and keep communicating with everyone.
"We're in touch with all the guys, to see what's available. We're still in touch with Nick [Fry] and Ross [Brawn] from Honda, because if someone buys them then potentially there will be something to look at for next year. There are many variables, and we just need to sort through them to get something out of it."
With two Jerez tests on the horizon, Senna said he would like to get out on track in F1 machinery again this year, but that it wasn't vital to his future plans.
"It's not a do or die situation for me," he said of the December tests. "Obviously the best situation for me would be to test with another team and do another good job, but I've already shown what I can do.
"Quite a few people were impressed with my results at Barcelona, and how close I got to Jenson for my first time in the car. In general, I've had good feedback from people inside and outside the paddock."
Senna added that his fallback position would be another season in GP2 with iSport, and that he would only settle for an F1 test deal if it had a racing element attached to it.