Including the retirement of Ben Rutten, the club has now made three changes to its list but says more are expected soon.
McKernan, 24, played two games for the Crows in 2014, bringing his overall tally to 36 in his six seasons at West Lakes.
Graham, 27, never made his Adelaide debut after being traded from Richmond at the end of 2012.
Crows head of football David Noble thanked both players for their contributions and wished them well in the future.
Twitter: @AFL_Harry
