Default [Q] Rear glass broken, problem for After sales services ?

Hello,

I recently experienced Micro USB problems with my Nexus 4. I mailed to the Google Play after sales services and they told me that they will replace my phone.

The fact is that my rear glass is broken (since more than 6 months and it was never a problem) but I do not know if they will agree to take back my Nexus under warranty.

What do you think that will happen if they refuse to take back my phone under warranty ?
Did anyone already experienced this situation ?
Thanks for you help.