The Chicago Cubs want to trade (away) third baseman Kris Bryant. One obstacle is Bryant's filing of a service time grievance. That calls into question the issue of of whether he has one or two years of team control left.
One possibility is that a team offers X, Y, and a PTBNL (player to be named later) for Bryant. That "player" is actually one of two possibilities: a good player, Z, if the ruling is in the team's favor, and a fringe prospect if the ruling is in Bryant's favor. That covers both possibilities. That is, Chicago gets X and Y for one year of Bryant, and X, Y, and Z for two years.
Is this possible? Has any trade been done like this in the past? Is there anything in major league baseball "rules" that would tend to prevent this going forward?