There's little doubt that the PS4 Pro, announced on Wednesday, is a spectacular 4K gaming powerhouse, but we were shocked to learn that it doesn't feature a 4K Ultra HD Blu-ray player for disc playback.

Considering the Xbox One S, which hit stores in August, does have a 4K Blu-ray deck, it seemed odd that Sony, a company with a vested interest in the technology, decided against following suit.

Now we know why.

Pocket-lint spoke to Masayasu Ito, executive vice president of Sony Interactive Entertainment's hardware engineering department, who told us that cost was a major factor in skipping the disc drive for this mid-generation machine: "It's a balancing act, you have to look at the cost and a 4K Blu-ray disc player would be costly," he said.

It wasn't the only reason though. Ito explained that PS4 users are also more likely to stream video than buy conventional discs: "We also considered user trends," he added.

"A lot of people are now just streaming 4K content and there's Netflix 4K HDR support from day one. So judging from what our users tend to do and looking at overall costs, this is why a UHD Blu-ray player is not included."

Pocket-lintMasayasu Ito-1

Matching a sub-£350 price point also meant that hard drive capacity couldn't be expanded for the Pro: "That was one of the main objectives. And, of course, a 2TB hard disk is still costly. This is why we decided on 1TB," Ito said.

"Having said that, as with the previous PS4, users are free to interchange and upgrade the hard disk to what they want."

The PS4 Pro will be available from 10 November, priced £349. It is capable of 4K HDR gaming and playback of streamed Ultra HD content from online services, initially Netflix and YouTube.