Restrict Service Supplier Sites from Indirect Requisition Creation

We want to prevent users from selecting SRV supplier sites during Indirect Purchase Requisition creation how we can achieve this.

For Example: Below SRV sites are created for Services but we do not want requisitioners to create requisition using SRV-Sites.

One Logic I can think of is creating auto rejection rule. Apart from this is there any way we can restrict requisitioners to choose this sites?