^indeed
the only kinds of players that are "must keeps" in the nba are superstars like lebron james, kobe bryant, dwayne wade, kevin garnett, tim duncan, etc. the rest are keepers if and only if there is no scenario in which you can improve your team by trading them, whether by addition or subtraction. for example, in indiana, trading down for peja stojakovic was an improvement because of artest's disruptive nature.