The dynamic fluctuation of the shape of a semi-flexible polymer in a non-local viscoelastic medium is analyzed. The advantages and restrictions of using a polymer as a probe to perform fluctuation rheology are considered. The polymer has an intrinsic elastic response, which acts as the reference for the measured viscoelasticity of its surrounding medium. Since the elastic restoring force depends on the wavelength of the fluctuations, shape fluctuation data from different wavelengths contain independent pieces of information. The viscoelasticity can be extracted from the data on the numerous internal degrees of freedom of the probe polymer, without using the analytical continuation method in the data analysis. The tension applied to the polymer also acts as an additional controlled variable in the experiment.