After his switch from Honda to Kawasaki's ZX-10R, Rea has won three races out of four to give him a comfortable early lead in the overall standings.
He acknowledges through that Sunday's third round at Motorland Aragon in Spain will likely be very competitive.
"I left Thailand with such a good feeling and I have been speaking with my guys already about the plan for this weekend," he told Crash.net.
"We need to start at zero again, not get carried away, and it is going to be super-tough. We are back in Europe where everybody has a lot of data, so it should be much, much more competitive.
"We just have to see where we stack up on Friday and Saturday and work methodically to make sure we have a package to compete at the front," he added.