It's a tough fight to call, but I say Collazo by stoppage. Khan doesn't seem to have fixed his flaws since moving to Virgil Hunter and his punch resistance is worse than ever if the Diaz fight is any indication. Collazo isn't a big puncher but he is a sharp one with good timing.
Don't know, Collazo is good fighter, Khan is very fast, has power. Question is; how much has Khan improved under Hunter?
Collazo is tough and I expect him to catch Khan with a powerful counter while Khan wails about with this chin held high. A TKO around rd8