As others are saying, La Boca is dangerous, but at the same time that doesn't mean you have to avoid it.
Buenos Aires can be a very secure place on one block and a really scary dangerous one on the other block, you have to learn how to navigate the city.
The same is true for La Boca. There are zones of La Boca where there is almost a 100% chance that absolutely nothing will happen to you, sadly the opposite is true for other areas of the neighborhood and the city.
If you can I would suggest going to La Boca with more people, either locals or if you are going with other tourists I would suggest going with some kind of tour (I know it's not that exiting, but going with a group of tourists without knowing the area is not a good idea). Also, even with a tour there are no really good reasons to go at night.
If you are planning to go to watch Boca Juniors the same applies. There are tons of "tours" to the stadium, but the best option would be to go with locals. If you know anyone in the city try to go with them. Usually they will know better than you the "codes" of the city, how to use public transportation to get there and if taking a taxi how to make sure it's a good one.
Please take into account that literally hundreds of tourists go every day to La Boca, although it sounds dangerous it's not a war zone, just be smart, avoid looking too rich or too poor and you will be fine.
You might want to consider taking the Yellow Bus. Actually they currently have a magazine only about La Boca (I have no idea how good or bad is it though)