Boston Globe:
Multiple Red Sox players confirmed yesterday that Thursday night's dugout altercation between Manny Ramírez and Kevin Youkilis resulted from Ramírez objecting to what he believed was excessive - and chronic - complaining about the strike zone by Youkilis in the dugout, as well as the first baseman's penchant for throwing equipment after at-bats.
Boston Red Sox - Behind the Youkilis-Ramrez fight - The Boston Globe