  WASP-10b, a non-inflated hot Jupiter, was discovered around a K-dwarf in a
near circular orbit ($\sim $$0.06$). Since its discovery in 2009, different
published parameters for this system have led to a discussion about the size,
density, and eccentricity of this exoplanet. In order to test the hypothesis of
a circular orbit for WASP-10b, we have observed its secondary eclipse in the
Ks-band, where the contribution of planetary light is high enough to be
detected from the ground. Observations were performed with the OMEGA2000
instrument at the 3.5-meter telescope at Calar Alto (Almer\'ia, Spain), in
staring mode during 5.4 continuous hours, with the telescope defocused,
monitoring the target during the expected secondary eclipse. A relative light
curve was generated and corrected from systematic effects, using the Principal
Component Analysis (PCA) technique. The final light curve was fitted using a
transit model to find the eclipse depth and a possible phase shift. The best
model obtained from the Markov Chain Monte Carlo analysis resulted in an
eclipse depth of $\Delta F$ of $0.137\%^{+0.013\%}_{-0.019\%}$ and a phase
offset of $\Delta \phi $ of $-0.0028^{+0.0005}_{-0.0004}$. The eclipse phase
offset derived from our modeling has systematic errors that were not taken into
account and should not be considered as evidence of an eccentric orbit. The
offset in phase obtained leads to a value for $|e\cos{\omega}|$ of $0.0044$.
The derived eccentricity is too small to be of any significance.
