If a multi-year keeper is traded to the NL, we have agreed that his salary should be wiped off the books for the next season. However, up for debate is if your keeper becomes a free agent and subsequently signs with a NL team during the off season (or is waived and then picked up by an NL team midseason) should that count against your auction budget for the next season?
In either case, I vote that we handle them just like a trade. Player have all sorts of club and player options at the end of their contracts so I don't think it's really feasible for us to figure all of that out. Plus, deals get restructured so what you thought was a lock for the 3 years is suddenly a free agent after 1.