I wouldn't go as far as to say Castro would have better defense than Fontenot immediately and Castro's speed isn't the greatest. Considering his prior experience at the upper levels, he needs to start in the minors, but be a possible promotion candidate come June if he's doing really well. With Castro there would be better defense at SS and I would think Theriot is pretty much equal to Fontenot at 2B. I don't see how Castro breaks camp on the 25-man without injuries. If the Fonenot/Baker platoon is scuffling then I could see a call up in mid May or early June. I don't have much faith in Fontenot to even be a average part of a platoon and think at best he is a 24/25 type player on a roster who starts maybe once a week. Castro made 39 errors last year in 119 games. He will probably be a very good defender, but he is by no means a sure thing to be an improvement over Theriot. That is true, but we all know how many errors Lee can save at 1B. I have asked this before on here, and never received an answer, what is the breakdown of fielding/throwing errors for Castro last year? Yeah, thats a good possibility, and I don't know if that breakdown is readily available without going through box scores. I just don't see a good enough of a chance of Castro performing better than the status quo right off the bat to risk stunting his development or starting his arb clock.