At its core is the belief that when it comes to the national team, a singular, focused commitment is required of all players - regardless of previous stature.
Landon Donovan did not show that level of commitment.
Now, there is no doubt that, even at age 32 and having lost a step, Donovan is still one of the top 23 talents in USA soccer.
But Donovan's desire for the game remains a question mark.
Looking back now, it is fair to say Donovan never regained Klinsmann's full trust when he took a 144-day sabbatical from the game, saying he was finding it difficult to motivate himself and had to rediscover his passion for the sport.
Well, that little journey in early 2013 occurred when the United States was in the process of trying to earn a spot in the 2014 World Cup, and, without Donovan, the USA suffered a 2-1 CONCACAF qualifier loss to Honduras.
It was a move Klinsmann deemed selfish and something he could never fully grasp, coming from a player of Donovan's stature as the face of USA soccer.
In Klinsmann's view, a player such as Donovan is supposed to set the standard for other players to follow.
Klinsmann was a world-class striker as a player. Strikers straddle a fine line between overconfidence and arrogance. One thing they never have is self-doubt.
Even though Donovan fought his way back into the USA mix by playing spectacularly last summer as the United States regained the CONCACAF Gold Cup trophy, Klinsmann likely never regained full trust in Donovan's total commitment to the game.
Donovan also has not been in great form for the Los Angeles Galaxy during the start of the Major League Soccer season.
And when Donovan did not set himself apart during the initial week of the U.S. training camp, it made it easy for Klinsmann to move on from him.
With 156 caps and 57 goals, including five in three World Cups, Landon Donovan will go down as the most successful player in U.S. soccer history.
But if the United States were satisfied with the level it had achieved during the Donovan era, then Klinsmann would not have been brought in to take it into the future.