Something like "well, if your client hasn't made up his mind by Feb 1, we'll just have to start looking elsewhere. If we find another guy we like, don't expect the offer to be there."
The only problem is that the Sox telegraphed at the start of the offseason that they wanted a power hitter and that their preferred guy was JD Martinez. Because of that, Boras realized he could just wait them out and keep playing the field as the Sox were probably not going anywhere else.