scraping noise in front wheel

[ta-all-the-way]

Hi, something is bothering me, pulled out of work today, Wet weather riding and down the road, Transalp, picked up a scraping noise in the front wheel. Couldn't even take the highway, I stopped at a garage down the way, The mechanic said it was a small stone caught in the brake pad. He cleaned them with some air pressure. Still scraping. I'm wondering if it's not small gravel in the wheel hub. So what do I need to do? Take off the wheel and redo the grease in the bearings? He said it would wear out, and not to worry. I would like to ride to work tommorrow with confidence. It's strange cause when I roll the bike backward it makes a slight knocking noise. I can feel it in the handlebars. It did seem better on the way home, less noise at higher speed. When I let down the gas, it comes back. It's not the front brakes cause it doesn't make a noise when I apply them. So it's definitely the wheel hub.

Any ideas or similar situations, what can one do? Thanks for any input
seeya

ta-all-the-way:confused1: