In regards to Mantei, I don’t really blame the guy. Bob Brenly stated that he would be the closer upon healthy arrival and then basically hedged his bet by instituting a all right handed closer platoon, the likes of which I’ve never heard of before.
Mantei’s criticism is along a long line of others (Sanders, Womack, Myers, Durazo, Swindell) who basically come to same conclusion: Bob Brenly doesn’t communicate well with his players. This falls directly in line with the character profile of a man who many (including myself) have described as anti-confrontational and very sensitive of criticism. The former forms a pattern similar to situation described to me by my father. During his numerous years of working in the medical field he noticed that doctors would very rarely confront other on a professional level, even if they were upset by a decision (etc.) that a colleague made. They didn’t have the same problem w/ nurses or other employees, as they would routinely berate them for mistakes. So as it pertains to Brenly, he seems to have a major problem confronting players and/or communicating their roles.
Unfortunately, the local media always lets such obvious comportment go unchecked, and, instead, we get erroneous excuses like "(the Valverde/Mantei closer dynamic) gives the Diamondbacks a bullpen similar to the 2000 Yankees." Brenly was referring to a Rivera/Nelson combo which is hardly similar to the current one in Arizona. That year closer Rivera had 90% of the Yankees 40 saves while Nelson had exactly 0. In short and unlike the current situation, their roles were clearly defined as closer and set-up guy. This is important as any good closer would tell you that they have to maintain the mentality of fearlessness and confidence, neither of which, in this case, is aided much by Brenly. Given this, it seems pretty obvious (in John Kerry-esque fashion) that Brenly's rationale was merely to hedge his bets so he would be immune from mass criticism. Think about it, if Brenly had given the closer role back to Mantei and he failed, some would scream at him for not keeping in Valverde (in the closers role). And if Valverde would have failed, some would criticize him for not sticking with the incumbent and/or giving a players job away while he was on the DL, a no-no amongst most major league player circles.
So it's easy to berate a player who vents during a winning streak. It's much harder, though, to get to the heart of issue, and discover that it has much more to do with a man that is seeking to avoid criticism then the man seemingly seeking it with some untimely comments.