I know nook has been basically horrid this year, but recently (in July, post baserunning gaffe) he hasnt done anything to hurt his situation.
In July, he's been hitting .304 with a .429 OBP and he's stolen his last six bases. He's raised his game in response to his job being in jeopardy while Langerhans has shrunk. I dont think it is a foregone conclusion that he will be gone when Esco gets here.
If we had a legit CF, Logan could be more useful off the bench than Langerhans. For the rest of this year Langerhans might be a better solution, but this isnt about this year.
Might have to keep Lnagerhans though. He is one of the featured acts of Hardcore Christian Day