Pitching fatigue question

[jlt53]

I have a team playing in the finals. Dale Murray is my top reliever. The team had a couple days off between series. Murray pitched in Game 1, did not pitch in Game 2, and pitched three innings in both Game 3 and 4.

What is his status for for Game 5? Is he able to pitch again at F9? Does he get tired faster than his R4 rating if he pitches 3 straight games? If he is fatigued already, should I change his settings to make sure Hal rests him in 5 so he will be rested for games 6 and 7.

I clearly have never understood the pitcher fatigue thing and would appreciate any advice. Thanks.