Tristan Thompson is putting down roots in L.A. -- and not far from estranged baby mama Khloe Kardashian's Calabasas home. The baller plunked down $6.5 million for a mini-mansion in Encino, presumable to be close to his TWO kids -- True, with Khloe, and Prince, with Jordan Craig.

While the Cavaliers player stays in his Cleveland home during the season, he apparently wants to spend time on the west coast during the off season and he'll spend it in a 9800-square-foot, 7-bedroom, 8-bath manse with a movie theater, pool, outdoor kitchen and more!

The home is about a 25-minute drive from Khloe's huge estate -- just enough distance so that he's not peering over her fence or knocking on her door to borrow sugar and closer into town so that when he goes on the prowl for girls at the clubs, he'll have a shorter drive home with his hoes. How practical!