The Costa Rica midfielder just returned from injury for yesterday's draw with Southampton.
"It is now going very well for me at Fulham, I feel great, even though I was injured. But in the first year I doubted myself regularly. Can I really do this? Am I good enough?
"If I doubted myself, I looked at the pictures of my time with Twente and I knew, yes I can really do this, I can score, I can play football," said Ruiz.