Starter: Rodney Hudson
Depth: Jon Feliciano
Hudson joined the Raiders in 2015 as the highest paid center in the league. Feliciano was drafted last year in the fourth round as a guard, but he can also play center as he did for rookie minicamp. After that it was Tony Bergstrom who was Hudson's backup, but he left as a free agent to sign with the Texans.
Hudson is one of the league's top centers and his contract goes through 2019, so his position is secure. He went down with an ankle injury late last season, making it abundantly clear that a viable backup center is a good asset to have. To Bergstrom's credit, he held his own. But there was a very noticeable drop off during the games either Hudson was playing hurt or Bergstrom was replacing him.
Whether the team actually sees Feliciano as the best option to back up Hudson remains to be seen. It would certainly make him more valuable to be able to be an interior swing guard/center. However, it would be worthwhile for the Raiders to add some competition there, preferably an actual center who can play some guard instead of the other way around. Perhaps in the later rounds of the draft.