I'm wondering if Mookie winning his arbitration would make him less upset or more upset.
If the arbiters agree with Mookie, then that reinforces his opinion that the Sox offered too little. If, OTOH, the arbiters agree with the Red Sox, then perhaps Mookie will think that the Sox offer was pretty much in line with what it should have been.
Either way, the best outcome would be for the 2 sides to come to terms before going to hearing.