What algorithms might be needed to build AI for a game like American Football in Unity?

I tried using built-in NavMesh but it failed at a point. You can also please suggest sources for learning about it.

  • Finite State Machines
  • Steering Behaviours

Chapter 4 has a full example of a football game that could easily be adapted to many sports: http://www.amazon.co.uk/Programming-Example-Wordware-Developers-Library/dp/1556220782