Xander Bogaerts is wearing the Under Armour Thief sunglasses. The good news is that they flip up for when you don’t need them and come with a back strap that can be easily taken on and off. The bad news is that these things are basically off the grid. They are out of stock on every site that has them listed.
If they ever restock them, use the link to check out a pair that we found on Amazon.