This has become something I pay attention to as much as any other performance metric when I'm putting together a roster. Sometimes if I have an older guy with marginal performance I will keep him on in a backup role just to have his leadership affecting the team. Occasionally when I lose track of the vibe and I see the team is struggling, shipping a guy out who has a low leadership/loyalty/work ethic combo makes an immediate difference.
I read a nice article about a guy who fills that leadership role, I thought I'd share
David Ross' retirement saluted on Instagram | cubs.com