Oscar and Tilapia

[goleafs]

I have an Oscar and a Tilapia in my 75 gallon tank. The Tilapia has been chasing the Oscar around whenever he sees him causing the Oscar to hide behind the heater and underneath the filter outlet. The Oscar is only 2 inches long and the Tilapia is 5-6 inches long. They have only been in the tank 3 days each. Is it safe to assume that once the Oscar gets bigger the problem will be solved?

[cocoa_pleco]

once the oscar is big he should be able to hold his own territory