The Costa Rican attacker cost the Southwest Londoners around £10.6million on transfer deadline day but he says he is happy to take the responsibilities that come with the territory.
"The club paid a lot of money for me, I know that, but it is a responsibility I am willing to carry," Ruiz told the club's official website.
"I will react positively and hopefully I can take the chance that I have been given.
"I know that a lot is expected of me, but I'm here to make a difference - I want to do all I can for Fulham.
"This is an exciting challenge for me, possibly the biggest of my career so far," Ruiz continued.
"I have signed for a team that is continuing to grow and one that offers so many possibilities.
"There were a number of things that attracted me to Fulham. Of course, there was the chance to play in the Premier League and for a manager that I have a lot of respect for. I know the way he [Martin Jol] works and I'm confident that I can do all that he wants me to."
Ruiz recently received his work permit to play in England and is likely to make his Cottagers bow at home against Blackburn Rovers on the weekend.
"I would love to be involved on Sunday, by which point I would have had a good few days of training with the team behind me," he added.
"I'm hopeful that I can play some part, but I suppose that is now down to the manager.
"I feel fit and ready, so we will have to wait and see. I know that I came in with a good goal scoring record, but there is more to my game - something I want to show from the off."