  In this work, we comment on two special points in the paper by S. Ghosh
[Phys. Rev. D 74, 084019 (2006)]. First of all, the Lagrangian presented by the
author does not describe the Magueijo- Smolin model of Doubly Special
Relativity since it is equivalent to the Lagrangian of the standard free
relativistic particle. We also show that the introduction of noncommutative
structures is not relevant to the problem of Lorentz covariance in Ghosh
formalism.
