For crying out loud. Grissom and Gonzalez both play 2b and both are righty hitters--and Gonzalez is a much better hitter than Grissom. So there is absolutely no need short of injury to have Grissom as backup. Hamilton, on the other hand,, is better defensively than either and a better baserunner. Plus he can back up SS.
The Sox owe Grissom nothing.