One day last summer Devil Rays pitcher Seth McClung took a no-hitter into the sixth inning.
 
The paper the next day reported that he wasn’t thinking about the no-hitter until some people in the stands started taunting him about it.
 
His quote about the situation made me smile:

“I kept telling myself the reason I’m throwing this no-hitter is because I’m executing my pitches. And when I wasn’t executing my pitches is when I wasn’t throwing a no-hitter anymore.”

A pitcher’s job is to execute pitches. Focusing on anything other than that detracts from his performance.
 
What are the tough innings for pitchers? Typically the first inning (understandable), the fifth inning when he’s ahead (thoughts can drift to getting the win), and the last inning (when “all I need to do is get these three outs and we win”).  
 
Also, any late inning of a no-hitter can be tough!
 
We’ve all seen it. A pitcher is cruising a long fine and then something happens that distracts his focus and he falls into one of three traps:

1. Primal Pitching: throws the ball harder -- like a caveman
2. Perfect Pitching: gets careful and tries to paint the corners
3. Prayer Pitching: loses his conviction and purpose, and lobs it up there hoping for the best.

The key to executing pitches regardless of circumstances is developing a pre-pitch routine that absorbs your focus.

I’m not talking about superstition (which is an appeal to some force outside of your control), I’m talking about a well-researched and well-practiced series of actions that maximize the likelihood of success.

In other words: a pre-pitch routine.  Would Tiger ever hit a golf shot without going through his pre-shot routine?

No.
Nor should you or your pitchers throw a pitch without going through a well-designed, well-rehearsed routine.