Blacked-out Boots for Messi?

It's a very rare occurrence that we see Messi sporting a pair of black-out boots. What could these boots possibly be?

 The Adidas Adizero is a very simple boot, one that is hard to improve on from its current state. That's why many people are very curious to what exactly Leo is carrying in this picture. Could it be an Adizero "2"? I don't see how Adidas could improve on their current boot, because it seems like the 5.6 ounce range is about as low as you can go before you start to sacrifice comfort and protection.

This leads some to a more outrageous sounding proposal. Could Messi possibly have switched to Nike? This would be an extreme move, along with a huge loss for Adidas. I highly doubt he made the switch, but you never know.

Here is another picture of Dani Alves in these mystery boots. He is also a known wearer of the Adizero. One quick little thing to think about: Messi and Alves are former Nike boot wearers. Could they both have made the move?