Microsoft's top Xbox chief Don Mattrick doesn't see Valve, and its in-bound Steam Box, as a competitor.

"No," Mattrick told The Verge when asked if Valve was considered a threat, although he noted Valve was "doing some innovative stuff".

So if not Valve and its much-anticipated Steam Box, set to go into prototype in the next four months, then what?

"The scale of products and things that are being brought to market are probably a little bit richer when I look at Sony, Nintendo, Apple, and Google," Mattrick said.

2013 is set to see the release of several gaming platforms including the PlayStation 4, the next Xbox, a raft of mobile-focused devices, the Android-fuelled Ouya and, of course, Valve's own Steam Box.

Most analysts are bracing themselves for fragmentation as experiments succeed and fail and business models rise and fall.

Microsoft, so far, has kept its next-generation gaming cards close to its chest. It is rumoured to be preparing to unveil its next Xbox at a special event at the end of April, although this remains unconfirmed for now.

Mattrick's comments come a month after Phil Harrison, Microsoft's new European game development boss, told an audience at an event attended by Eurogamer that Valve and other companies working on new gaming hardware face a number of issues entering the market.

"Entering the hardware business is a really tough business," Harrison said. "You have to have great fortitude to be in the hardware business and you have to have deep pockets and a very strong balance sheet. It's not possible for every new hardware entrant to get to scale.

"They can be successful at small scale. But it's very rare for a new hardware entrant to get to scale, and I mean tens or hundreds of millions of units. There are a very small number of companies that can make that happen.

"And it's not just having a great brand or a great software experience. It's about having a supply chain and a distribution model and a manufacturing capacity and all the things that go with it. It's a non-trivial problem to solve and it takes thousands of people to make reality."

Despite not considering Valve a threat, Mattrick was quick to highlight his admiration of its influential co-founder Gabe Newell, who last night was in London to receive a BAFTA fellowship for his work in the industry.

"I love Gabe," Mattrick said. "I was there for his lifetime achievement award so it's wonderful to see what they're creating."

Newell has been vocal in calling for Microsoft, and other game console manufacturers, to open up their platforms. Xbox Live Arcade - and indeed the Xbox Live digital platform - has since its inception been a closed platform, preventing developers from self-publishing, updating games as they see fit and patching in a timely fashion.

Most observers expect the next Xbox to break down these barriers, taking a more App Store-style approach, but comments from Mattrick suggest Microsoft is keen to keep XBL under a curated lock and key - a strategy that seems to contrast starkly with Sony's more open approach with the PlayStation Network.

"There's a certain level of technical and production competency that people have to get through because we're trying to curate great experiences," Mattrick said.

"We're trying to make sure that what exists upon our service on our system is done to a quality level and has interest for people who are likely to use it."