A method of trialing prosthetic components of a knee prosthesis including positioning a femoral trial component on a surgically-prepared distal end of a patient's femur, assembling a tibial bearing trial component, and positioning the tibial bearing trial component on a tibial base trial component seated on a surgically-prepared proximal end of a patient's tibia. The method may also include adjusting the patient's leg with the tibial bearing trial component engaging the femoral trial component, and readjusting the patient's leg with the tibial bearing trial component engaging the femoral trial component after positioning the tibial bearing trial component on the tibial base trial component and a keel punch.