Evans
Trades for a young player with potential (Robinson, Williams, even Vesely)
Aminu and MAYBE a backup point.
The team is good enough to win as is. They just need to grow more. As Duncan ages, Splitter and Baynes should get better. As Ginobili and Parker decline, Green and Leonard should take bigger roles. De Colo and Joseph should be better next season as well. The team is in position to use their cap space on the best player available. They don't have any needs that won't be fixed with the minimum. They should just look for talent, potential and value this off-season.