The Lancaster is a great hotel, if you're willing to spend the money. Actually, walking to/from there is not bad, but if it does worry you it would not be an expensive cab ride from there. After the game you could probably take one of the bicycle taxis (I'm sure there's another name) that always line up on Texas.

The Hilton by Toyota is a fair walk, and I would not be quite as comfortable walking that direction.

Actually, I think the concerns about walking in downtown at night are a bit overstated, especially along Texas after a game. There are a lot of people, not just leaving the ballpark, around that area, and I've not heard about much street crime. Don't go north of the park, however. That gets dicey very quickly.