Garrett’s return in a reboot of the Thief franchise is a pretty hotly-anticipated affair, moreso if you’re one of the lucky few to own a Mantle-capable GPU such as the Radeon R290X.

AMD’s graphics API provided a pretty significant boost to the other Mantle-compatible game currently available – Battlefield 4 – and gamers are no doubt looking forward to seeing similar gains in the upcoming stealth-romp Thief.

The new game is due to launch in North America on the February 25th, so it’s rather surprising, with only three days left, to hear from our contacts at AMD, referring us to a newly-updated system requirements page, with a last-minute note that Thief won’t be shipping with Mantle support:

Important Update Regarding Mantle and TrueAudio

THIEF is a showcase for the awesome gaming performance offered by the PC and we’ve worked hard with AMD to accomplish that, by collaborating on the implementation of several PC-specific features. This includes AMD TrueAudio technology, AMD CrossFire™ technology, AMD Eyefinity multi-display technology and more. As you know, THIEF will also be one of the first games to ship that takes advantage of AMD’s Mantle graphics API.

We’re extremely proud of the work we’ve done with AMD to make the PC version of THIEF a stand-out, definitive experience although we have a little more work to do to accommodate all of these new PC-specific features – we are busy working on a patch to support AMD’s Mantle and TrueAudio technologies that is scheduled for March. We’re confident this patch will ensure the best and fastest THIEF experience for AMD Radeon™ customers. We’re sorry we couldn’t bring this to you sooner – although we will use this time to bring you the very best experience possible and will let you know when the patch is ready.

We’re happy to say that the AMD CrossFire™ technology and AMD Eyefinity multi-display technology will be fully functional when THIEF launches on the 25th February in North America and 28th February in Europe and other associated territories.

No word yet as to why Mantle support has been delayed, it’s a pretty subtle change in wording, going from being the “first game to ship with Mantle support” to “one of the first games to ship that takes advantage of AMD’s Mantle”, either way it’s going to be a pretty big disappointment for some.