Spotted by Thurrot.com, Nadella reveals in his new book, Hit Refresh, that he voted against the acquisition when then-CEO Steve Ballmer conducted a straw poll of members of his senior leadership team on the topic.

I voted no. I did not get why the world needed the third ecosystem in phones, unless we changed the rules … But it was too late to regain the ground we had lost. We were chasing our competitors' taillights.

We've heard something to this effect going as far back as 2014 in a Bloomberg report, but it's interesting to get some insight through Nadella's own words. At the time, even Microsoft co-founder Bill Gates was reportedly questioning the deal, so Nadella wasn't an outlier.

As Microsoft watchers are well aware by now, the company would go on to write off the Nokia acquisition amid a spate of thousands of layoffs. The state of Windows phones has continued to decline since.

In his book, Nadella also echoes a sentiment that he has expressed before — that Microsoft should look to enter the phone business with something that truly sets the company apart.

Buying a company with weak market share is always risky. We should only be in the phone business when we have something that is really differentiated.

Depending on how you choose to read Nadella's comments, there could yet be a glimmer of hope for Microsoft fans hoping to see the company return to the phone business in a meaningful way. The mythical "Surface Phone" has been rumored for some time now, and it could represent a chance for Microsoft to introduce something that sufficiently differentiate's the company from other players in the mobile market.

Should Windows phone fans be optimistic about Microsoft's mobile strategy?

Hit Refresh is set for release on September 26 and is up for preorder now starting at $15.99.