Lineker.
I'm not sure what Garbrandt has done to deserve a fight with John Lineker. Lineker was a Top 5 Flyweight, and should now be a consensus Top 10 Bantamweight. Garbrandt doesn't even have 10 fights yet, and nothing anywhere close to a Top 20 win, let alone Top 10.
Lineker should be fighting Jimmie Rivera, Thomas Almeida, or Aljamain Sterling. Fellow young BW's who are actually Top 10 fighters.