I've been saying this below for some time-
"I think Greg's actually pretty good defensively," Van Gundy said. "I've thought that all year. He's a very good low post defender, in my opinion. And he's a smart defender. He doesn't make a lot of mistakes [...] His mental approach and ability makes him a solid defender."
Grantland's Zach Lowe, like Van Gundy, also praised the bigman's defensive energy, pointing out that Monroe is an especially good pick-and-roll defender. Greg has a career 106 Defensive Rating. For comparison, fellow Pistons Andre Drummond and Joel Anthony boast ratings of 102 and 104 respectively, while last year's Defensive Player of the Year, Joakim Noah defended his way to a 96 rating. If those numbers prove anything, it is that Monroe isn't a total defensive liability as some would lead you to believe, but an unheralded defender who knows how to hold his ground.