Here's a funny anecdote I got an email about from a good friend who works at ESPN:

"met Tim Kurkijan for the first time in person tonight and he is one of the most legit dudes out there we were just shooting some sheeze and I said I'm from TX and he told me something I'd never known, that he was Beat Writer for the Rangers from 83-85 and then he lived in Dallas during the early 90s while writing for SI so anyway I said something along the lines of "oh yeah, the Igor Era....fightin' for them RBIs..." and he just goes OFF into this long tale about his days interviewing Bobby V and how Bobby always had to deal with the jealousy between Ruben and Juan....so much so he actually had to stick Kevin Reimer after Ruben in the order cause if Ruben knew Juan was right behind him and there was a runner on third and less than two outs, he'd swing at (quoting Tim quoting Bobby V) "Any crap they throw up there" desperate for a Sac Fly instead of taking pitches and walking like he should....all because he just didn't want Juan to get the RBI!! Quoting Timmy K again (in an incredulous voice) "Sierra didn't care if Reimer got the Sac Fly behind him, he just didn't want it going to Gonzalez!!"'

Perhaps an additional reason why Sierra got shipped out?