You're a good man Charlie Brown !
I think it is to your credit you are concerned about it. But since it was not your intent in dropping the player, and assuming you are not running two teams in the same theme or progressive league that you are doing this for, I think it is okay.
When I play OOTP Baseball, one of the big issues is that that game's AI sometimes has some gaps in evaluating future stars and will offer you say, a young Ken Griffey Jr. for a third-string utility player that another team needs. Since you are playing against the AI, ethics issues come up - the AI only knows ratings, you know players, and you know that KG Jr. IS KG Jr., while the computer does not.
So online there are many discussions about under what circumstances you are acting ethically to take a trade offer that is in your favor, since after all that IS why you trade in the first place. But where is the cut off, the line that you shouldn't cross?
Probably this is a missing element of Isaac Asimov's rules for robots, but we are all preparing ourselves for the near future of human-algorithm relations, and what the ethical standards should be.