Headlining the list were the consensus top position and pitching prospect, Anthony Alford and Conner Greene. Both likely start the season at AA New Hampshire, and it's conceivable both could figure into major league plans later in the year if they build on their breakout 2015 seasons. Alford, a 2012 draftee out of high school, will be rule 5 eligible next winter and will be added to the 40-man, so he could very well be added early as a September call-up.
There were three other pitchers invited: RHPs Wil Browning and Taylor Cole, as well as LHP Chad Girodo. Lefty specialist Girodo could figure into the 2016 big league roster, though appears blocked with Aaron Loup an established lefty specialist (even if Gibby doesn't always realize it).
Two catchers were invited, Derrick Chung and Danny Jansen. For Jansen in particular, who spent 2015 at Lansing and lost a good portion of the season to injury, this will mostly be about having extra guys to catch all the pitchers in camp.
Finally, seven other position players received invitations: IF/UT Jon Berti, IF Andy Burns, 1B Matt Dean, CF Roemon Fields, OF Dwight Smith Jr, DH Rowdy Tellez, and SS Richard Urena. Burns strikes me as the likeliest to figure into 2016 plans, as he can play at around the infield and has a full season at AAA under his belt. Smith Jr was not protected from the 40-man, but with a good AAA season could figure into the second half plans in the event of significant injuries thinning out the ample OF depth.
Berti and Fields could see call-ups especially later in the seasons. Fields in particular could be a pinch running weapon off the bench late in games like Dalton Pompey was in 2015. For Dean, Tellez and Urena, this will be more about getting acclimated as none will start higher than AA.
For me, perhaps the most interesting is not a name on the list, but a name omitted from the list: Sean Reid-Foley, their second round pick in 2014 who dominated low-A (90K in 63 IP) but struggled more with control upon his midseason promotion to high-A. If there a candidate to make a big jump from the low minors to reinforce the big league bullpen, a la Osuna and Castro, Reid-Foley was the most likely candidate. But we can now rule this out with him not even being invited to big league Spring Training (though it wouldn't surprise me if he got into a couple games). Perhaps this is also a tangible example of a new, more linear and measured approach to player development by the new management - which I for one would strongly welcome.