You can select a mesh and then hit convert to TS
But you cannot select convert to TS and then select the mesh.
Both options should work because ofther wise a user could think the
mesh cannot be selected to convert.
Also from a logical standpoint there is no reason why after selecting convert to TS command
I should not be able to select the mesh to convert to TS.

Video:
https://drive.google.com/file/d/0Byzv_NlyKp_2eWJQTnU4ZTRDUjQ/edit?usp=sharing