I would suggest against turning them into a tunnel. Actually, I would advise against keeping it at all. If you listen to the Valve commentary, they talk a lot about keeping the level simple. If you look at something like dustbowl or goldrush, there's maybe an alternate path through the level, nothing more. I think it would be better if you removed the two rooms entirely, and put the healthpack somewhere more visible. Just my 2 cents.