Rafaela isn't ready today. If he becomes ready, they push him to CF and Kiké goes to SS. Arroyo just can't handle a fulltime workload.
At some point, we may see Rafaela in CF and Mayer at SS this season. People will say I'm crazy, but that's what I'm going with. I think Mayer's bat is more likely to be MLB ready than Rafaela's.