Tristan Thompson and Khloe Kardashian aren't back together, but that hasn't stopped the NBA player from admiring his ex's bod ... 'cause he gushed over the latest pic of her physique Wednesday.
Khloe posted a sizzling photo of her on the cover of Health mag on her social media page ... and just minutes later, Thompson hopped in the comment section with a sweet compliment.
"Wow!!" Thompson wrote. "You are so motivational Koko!