AP
Speaking to reporters ahead of SAP's annual meeting, McDermott was asked what would happen to his company's own business if a rival like Microsoft acquired Salesforce.
The SAP CEO bluntly replied that he did not think a merger would happen, by Microsoft or other rivals such as Oracle.
"I do not expect that to be the case at all because of the valuation of the company," McDermott said referring to the possibility Microsoft would buy Salesforce.
He was then asked whether any rival would buy Salesforce and he responded: "No."
Pressed further on the possibility Oracle might buy Salesforce, McDermott responded: "It is probably better than any [other] scenario for SAP because it will add more disruption to a commodity business."
Salesforce has a market cap of close to $50 billion, but analysts predict a takeover premium could push up the value of a potential deal to $60 billion or more.
News first emerged that Salesforce had hired advisors to consider, and perhaps fend off, a possible takeover offer on April 30.
Since then the tech industry has been awash with gossip and theories about what might be happening. Potential rumored suitors include Microsoft, SAP, Oracle, IBM, and Google.
Salesforce is due to report its first quarter results on later on Wednesday.