Doc Rivers Praises Kate Upton For Defending Fiance

Doc Rivers ain't buyin' the argument that athlete spouses should keep their mouths shut -- and just praised Kate Upton for GOING OFF on MLB for snubbing Justin Verlander.

Upton went nuclear on Twitter Wednesday night -- claiming her fiance got majorly f'd (yeah, she dropped the f-bomb) because JV clearly deserved the Cy Young Award ... yet somehow came in 2nd.

With Ayesha Curry taking heat for her Twitter rant during the NBA Finals -- we asked how Doc felt about the situation.