Maybe he meant Werth?
Seriously though, regardless of his comments, I still think that the team needs to find a lead off hitting second baseman and can move on from Denard. I really like Denard, but I don't disagree with what Harper said. Zim is much less of a liability defensively in LF than at 3B. Rendon's value is maximized at 3B over 2B as he is better defensively at 3B (bat plays regardless). Zim's bat looks better in LF than it does at 1B. LaRoche shouldn't be benched as he is still hitting really well. Span is a better hitter than Espinosa, and maybe you keep working in ways to rest one of LaRoche or Werth until the trade deadline, but Rizzo really should be looking at a replacement at 2B, even if it is a rental like Zobrist.
I would say that the best option is Mookie Betts at 2B, but the Sox will play Betts in the OF since no one in that lineup is actually hitting and they would want something good in return, most likely good pitching.