Recently, Joel Sherman of the New York Post talked to an NL GM who said he does not expect a robust market for rental players this summer. Under the previous collective bargaining agreement, players acquired in their contract years could still be more than rentals due to draft pick compensation. But due to a rule in the new CBA, a rental is truly a rental for the 2012 trade deadline: traded players are not eligible for draft pick compensation. As Sherman notes, that adds extra appeal for someone like Matt Garza — a team acquiring Garza can enjoy him for the rest of 2012 and all of 2013 and then receive a draft pick as compensation if he departs as a free agent.
Keep in mind that for a team to receive draft pick compensation for a departing free agent after the 2012 season, a qualifying offer in the $12.5MM range must be tendered. Since that amount represents an average of the top 125 salaries, it will increase every year. It could be dangerous to surrender quality prospects for Garza now partly due to the assumption that he'll be worthy of a $13-14MM qualifying offer after the 2013 season.
Still, take a look at our list of players who, like Garza, project to be eligible for free agency after the 2013 season. Which could be acquired with a partial eye on draft pick compensation after '13? Chase Utley has a good amount of no-trade protection, and given time missed due to injury and reduced production, it'd be optimistic to expect a qualifying offer. Hunter Pence, on the other hand, is a decent bet for such an offer. Among position players, Corey Hart also has a shot. Both outfielders figure to be part of their team's 2013 plans, however.
Aside from Garza, Josh Johnson is a starting pitcher to consider. Johnson has been uncharacteristically hittable this year, but he has been healthy and stands as a candidate for a qualifying offer after '13, should the Marlins decline to extend him again. Despite their all-in offseason, the Marlins appear a long shot for the playoffs, it is possible they could move Johnson for MLB-ready players. Jason Vargas has been a hot name on the trade market. While I think GMs would find it appealing to control Vargas for 2013, I doubt they would have any expectation of making him a qualifying offer afterward.
We haven't discussed Justin Upton types, players who are under control beyond 2013 and seem to be reasonable candidates for future draft pick compensation. Those are rare players. Looking only at trade targets eligible for free agency after 2013, the qualifying offer will be a pretty high bar, and future draft pick compensation can't be a primary consideration for an acquiring team.