The Teessiders went down 2-1 to Simon Grayson's men at the Riverside Stadium on October 16 as Gordon Strachan's ill-fated reign drew to a close. But the Argentinian is confident significant progress has been made ahead of the New Year's Day clash at Elland Road.
Arca told the club's official website: "Leeds are probably one of the best teams we have played this year. They play good football and have two good strikers.
"But it's good to go there with the way we have been playing recently rather than the way we were playing two or three months ago.
"Passing football and trying to create chances at the right moment - that's the philosophy the manager [Tony Mowbray] is trying to introduce. It's working because we have the players to do that.
"Once the players realise we can do it, it won't be easy, but it's going to become a lot more comfortable."
Source: PA
Source: PA