Are there missions in Starcraft 2 that prevent you from playing others?

Question

With the exception of the missions that explicitly give you a choice and make it obvious that one mission will prevent another (specifically, not different missions, just different objectives/rewards etc) are there any missions that, by choosing to embark on them, prevent you from performing other missions? Without giving away any spoilers, there is specifically one instance I can think of in the campaign where I could see this happening, but it was never explicitly stated that choosing one mission over the other would create a permanent fork in the story line.

Does anybody know for sure (or perhaps know what I'm referencing)?

Thanks! Chris

Answer 1

There is one mission like that in the final few missions that give you an option between 2 missions and depending on what you choose it makes the next mission change a bit, but it is still the same mission.

There is also one hidden objective in one of the missions that will give you access to a secret mission that can only be played by completing this objective, this mission however is not crucial to the story.