It's hard to compare them, because Dependency Injection is much more high level than Command.
The most obvious similarity is that they make use of
polymorphism, of course. Other than that, I'd say that they solve rather orthogonal problems.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus