Should a table have a clustered index even if it doesn't have appropriate fields for it?
1) IF PlayerId is assigned with NEWSEQUENTIALID, you could consider that as the clustered index.

2) Otherwise, you can add an IDENTITY and make that clustered (questionable benefit, since all access will be through the PK you have already established).

3) Or you can leave it as a heap - with appropriate non-clustered indexes.

My order of preference would be 1, 3, 2 assuming you can't change the uniqueidentifier to an IDENTITY instead.

Can you explain why you are using uniqueidentifier in the first place? - that may have some bearing on this.