Jared Veldheer according to Rotoworld is considered one of the better tackles in the league when healthy. He doesn't want to be tagged, and may not be seeing that the Raiders have to worry about re-signing Lamarr Houston as well. They may let both test the market, but would probably choose Houston if the choice just had to be made. But, just think about the possibilities with tags, Hardy, Veldheer and perhaps Houston in the mix. Moreover, throw Denarius Moore in the mix, and perhaps something could be worked out.
Just food for thought for active imaginations.
Ultimately, Veldheer may be a decent option to replace Gross, irrespective of any of my multi-player musings, if he is allowed to hit the market.