Jari-Matti Latvala said there was no way he could have avoided the rock that caused the suspension damage which cost him the Rally Mexico lead.
Broken front suspension dropped the Ford driver from first to eighth on the final stage of the morning loop in Mexico today.
"It was in a really fast section of the last stage," Latvala told AUTOSPORT. "I came downhill then up over a flat-minus over the crest. I had a small rock marked in the notes, but only if you cut the corner. On the line, in my notes, there was nothing. But when I come in the rally, on the line there was a big rock.
"I thought it had come down from a mountain. I tried to avoid it, but I had so much speed and it was so, so slippery, I couldn't go out and around it because I would have gone into the loose and gone off the road. So I hit it."
Latvala added that he now just wanted to salvage as much as possible from the event, having fallen 1m32.8s off the lead.
"We have to try and lift the position, but unfortunately we are out from the victory battle - but we have to get back to the good position as possible," he said.
The Finn also said Ford could take comfort from the fact it was quick enough to lead in Mexico, an event Citroen has dominated in recent seasons.
"It had been great," said Latvala. "There were some positives from the start of the rally and there is still a long way to go - we will try to hold it together."