"They will continue to do their one-twos," Lopez told Germany's Auto Motor und Sport.
"Red Bull has also made great progress so they will also be difficult (to compete with). But behind them it is interesting," he said.
Indeed, after a disastrous start to 2014 for the Renault-powered team, Lotus is finally beginning to make progress, with Romain Grosjean fighting in the points in China until his retirement.
"Ferrari has good results thanks to Fernando (Alonso)," said Lopez. "Williams' advantage is due to the engine, but Force India has a good car, otherwise they would not be third in the championship.
"Of course there are many factors, but I think we can deal with those teams," he claimed.