I know exactly what the problem is. I've seen that happen with a couple of people's M11s (including mine). It isn't your bearings, but you do need to take the wheel off. Your wheel must have taken a bit of a hit (can be just from it falling over or could have happened during travel). The part that the wheel is connected to gets pushed in a little. This causes it to stick a little.

To take the wheel off you just need to remove the cover in the center of the wheel. You may need to take a little screwdriver to pop it off. There is a phillips head under the cover. Now take the phillips head screw out. After you take the screw out the wheel comes right off.

Now what you need to do is grab the part that the wheel was connected to with a pair of pliers and pull it back out until it pops back into place. It does take a bit of force.

Put it back together and you should be all set!