His teammate had a strong response Monday when asked whether Thompson deserved the defensive honor.
"Yeah, but the people that vote on that don't really know the game," Durant said, per Connor Letourneau of the San Francisco Chronicle.
While Thompson is often overlooked offensively with Durant and Stephen Curry on the team, and defensively alongside Draymond Green, his work was on full display in Saturday's win against the Oklahoma City Thunder.
The five-time All-Star mostly matched up against Russell Westbrook and held him to seven points on 2-of-16 shooting from the field, which helped keep the Thunder to just 88 points for the game. He spoke about his play after the game:
MVP candidate James Harden has also struggled against the Warriors, shooting only 39.7 percent from the field in his three games.
"There's not many guards that is better than Klay defensively," Green said Saturday, per Mark Medina of the Mercury News.
Thompson earned eight first-place votes for the All-Defensive Team last year, although it wasn't enough to beat out guards Victor Oladipo, Jrue Holiday, Dejounte Murray or Jimmy Butler for a spot on one of the two lists.
Perhaps his impressive work against the biggest names in the NBA will help get him more attention by the time votes are cast for 2018-19.
Of course, it's possible Durant is also upset that he has never earned All-Defensive Team recognition either, and this is his way of calling out voters on behalf of his teammate.