(SOLVED) My mesh floats ingame? Help please! :)

I have been working on a watch model and I have created the mesh and started texturing. However when I tested the mesh ingame the face of the watch floats and is detached from the strap. The mesh is a modified mesh of the get famous fancy watch, I deleted the face of the watch then created my own to get the shape of the watch which is modelled after an Audemars Piguet.

I have provided images below to show what I mean.

This is my first time creating something in blender so I must have missed something when creating this mesh. Help would be much appreciated