At all times a major league baseball team has to have a valid 40 man roster. During the season, the team can place injured players on a 60 day DL and open up a spot on that roster. Once the season is over (2 PM PT on the 5th day following the conclusion of the World Series, to be specific), the 60 day DL goes away. All those players either need spots on the roster or have to be let go. Most years the team also has a number of free agents that vacate roster spots at the same time. The Padres do not have this luxury this offseason. They will either have to make some trades or designate guys for assignment to remove them from the 40 man roster.
The team only has one true free agent: Tim Stauffer. They could add one more if they decline Josh Johnson's $4M 2015 option (a player who also happens to be on the 60 day DL). Not including Johnson there are 5 players on the 60 day DL: Casey Kelly, Cory Luebke, Yonder Alonso, Ryan Jackson and Carlos Quentin. Some simple math (40 - 1 + 5) shows that the roster crunch comes down to at least an extra 4 players. But who could they be?
I can eliminate a number of what I think the org would deem essential players or prospects from consideration: Alvarez, Benoit, Cashner, Despaigne, Erlin, Hahn, Kennedy, Quackenbush, Ross, Thayer, Torres, Vincent, Wieland, Grandal, Rivera, Amarista, Cabrera, Gyorko, Medica, Peterson, Solarte, Spangenberg, Almonte, Liriano, Maybin, Seth Smith and Venable. While not every one of those players is guaranteed to be a part of the 2015 team, all mean more to the org than to dump them at this point. The next tier, if you will, are a number of players that are less established as either prospects or major leaguers or are part of the walking wounded, but also seem unlikely to get the boot at this time: Alonso, Boyer, Campos, Garces, Kelly, Luebke, Roach, Burch Smith, Asencio, Fuentes, Goebbert. A couple of those I am more sure about than others. So that should leave us with a list of bubble guys.
That list is: Juan Pablo Oramas, Keyvius Sampson, Eric Stults, Adam Moore, Ryan Jackson and Carlos Quentin. Oramas is a Tommy John survivor who struggled in AAA last year. He wouldn't be my first choice to cut, but I can't rule him out. Keyvius Sampson was once a promising prospect, but two bad trials in AAA leave him far removed from the last time he showed he belongs. Eric Stults is a non-tender candidate due to increasing salary and an increasing standard of production for the starting rotation, but the team could cut him early and free up a roster spot. Adam Moore was a late season roster add to increase catcher depth and at 30 years old he seems like an easy cut. Ryan Jackson was the return in the Jesus Guzman trade and was supposed to back up Cabrera at SS before missing the entire season with injury. A weak bat, a year off and an org that hasn't seen much of him makes him vulnerable. Everyone who follows the Padres knows that Quentin's career has nosedived and it's a matter of when, not if, the team decides to cut ties with him.
Prediction (assuming there no trades): Sampson, Moore, Jackson and Oramas get designated for assignment. Quentin gets a small reprieve. Stults decision gets pushed.
The Padres also may need additional roster spots if they want to protect players from the Rule 5 draft (Taylor Lindsey, Stephen Kohlscheen and Alex Dickerson are players that would require roster spots if the Padres don't want to risk losing them), so it may end up being more than just the 3 roster spots needed. However the last day to protect players is November 20, so that crunch comes a bit later.