MINNEAPOLIS — Nets that don’t play hard all the time are going to have a hard time playing.

So says the mentor who best knows new Brooklyn interim head coach Kevin Ollie.

Ollie played for — and won under — Jim Calhoun at UConn. Then he served as an assistant coach under Calhoun in Storrs, before eventually succeeding him as the Huskies’ head coach. And through all that, Calhoun told The Post he saw Ollie work, work and work some more.

And he’s fairly sure the Nets’ new coach — named to replace the fired Jacque Vaughn last Monday — is going to demand the same. It’s what he demanded of his UConn team that he coached to a 2014 NCAA title.