Slew was signed on transfer deadline day from Sheffield United.
Kean sat down with Slew last week to discuss his plans for the forward and told the Lancashire Telegraph: "We'll feed him in slowly and bed him into the group, but I spoke to him for about an hour and I said you adapt quickly and get in.
"It doesn't matter about your age, don't think you're sixth choice because you've got the four established ones there and Nicky Blackman here before you.
"Just get in, hit the ground running, get your goals and he's got a great chance to play.
"He has strength, he wants to get in behind defenders and I think he's a dynamic powerful young striker. He's certainly one for the future."