His value can't be that high since he's a UFA next season.
My opinion may be a little clouded since I get the impression that he and Trotz don't see eye to eye. I wouldn't be surprised to see him walk next season since he may think he doesn't get enough quality ice time, whether it be because of forward depth or Trotz.
That was last season, Hartnell has one penalty in 8 games. He's getting time this year and has been one of our better players. He'll be resigned, just like Zidlicky. He's also in the top 6 in ice time and is on the second pp unit.