Willis (neck) will not be available Saturday, Adam McCalvy of MLB.com reports. It's uncertain how much time Willis, who's in Brewers camp as a non-roster invitee, may miss as a result of this ailment, but it could hurt his chances of earning a bullpen role if it lingers for a week or more. The 33-year-old Willis threw his last pitch in the major leagues on Sept. 25, 2011.