Why did you not go to a game? You would say you were "not able" if you were too busy with work or other obligations, or could not get tickets or some reason like that.
If you simply did not take advantage of the opportunity, then you were "able" to go to a game.
You would regret not actually catching a game.
Were you in Pittsburgh? Then you would have wanted to see a Penguins game. Not a game "against" them. Unless you were a fan of the visiting team and wanted to see your team play against the Penguins.
Finally, Pittsburgh has an "h" on the end. It is the only "burg" in the US that has an "h." The federal government took it away for a while in the early 20th Century (in the service of uniformity), but we complained so much that they gave it back.