I just took over a team and a very good player played every day in his rookie season last season. The team is not going to contend this season and I would like to preserve the "extra" season of control I can get from having him be in the minors part of this season. His ML service time is currently 1.004 so I think I need to hold him in AAA 24days to avoid getting 1 full season this season? Sound right? Thanks.

 

Still just 20.  172 days is a service year, full season is 176 days, so you'd really only have to hold them back 13 days (to cover the 4 extra days over 3 years before entering arbitration), but a stint in the minor leagues has to be at least 20 days to not have it count as Major League service time.