Efficiently randomly sampling List while maintaining order

I would like to take random samples from very large lists while maintaining the order. I wrote the script below, but it requires .map(idx => ls(idx)) which is very wasteful. I can see a way of making this more efficient with a helper function and tail recursion, but I feel that there must be a simpler solution that I'm missing.

Is there a clean and more efficient way of doing this?

import scala.util.Random

def sampledList[T](ls: List[T], sampleSize: Int) = {
  Random
    .shuffle(ls.indices.toList)
    .take(sampleSize)
    .sorted
    .map(idx => ls(idx))
}

val sampleList = List("t","h","e"," ","q","u","i","c","k"," ","b","r","o","w","n")
// imagine the list is much longer though

sampledList(sampleList, 5) // List(e, u, i, r, n)