Jaime Alguersuari admitted that he was uncomfortable with his Toro Rosso's setup in Indian Grand Prix free practice, having crashed in the morning session.
The Spaniard lost control at Turn 9 in the opening session, and was 14th fastest in his repaired car later on.
"We tried a setup today that did not suit me and I found it quite difficult to keep the car in a straight line out there," said Alguersuari. "I did not feel comfortable and I felt I was on the edge. In the morning, I went over it, losing control and hitting the barrier with the rear of the car at Turn 9.
"The guys did a good job to get it all repaired for the start of the second session. I am sure we can have a better feeling for the car tomorrow and improve our position."
His teammate Sebastien Buemi was 10th quickest and more upbeat.
"I think we have everything we need in terms of data and understanding to prepare ourselves for qualifying and the race," said the Swiss driver. "I am happy with the way today went overall, the car ran reliably and the team did a good job. Now it's up to us to put everything together for qualifying. In terms of performance we hope we can continue the trend we saw in Korea."