Small forward Ryan Neates has been delisted after three injury-plagued seasons at the club, while rookies Michael Mascoulis, Anton Hamp and Callum Papertalk have been cut.
Stevens, who was recruited with pick No.23 in the 2009 NAB AFL Draft, is seeking to continue his career at another club after completing his end of season interview with West Coast.
The Victorian played just 11 games in three seasons and West Coast list manager Craig Vozzo said the club would begin negotiations with potential suitors for the strong-bodied on-baller.
"Unfortunately, Koby has informed us that he would be seeking to be traded to another club in pursuit of further opportunities," Vozzo said.
"That's extremely disappointing because we saw him as an important player in a developing midfield.
"Koby is a young player with some terrific attributes and we had hoped he would remain with our club to be a part of what we believe we are building towards.
"Having said that, we understand and respect Koby's decision, and will work to ensure a suitable outcome for all parties."
A tough, inside midfielder, Stevens played just four games this season, three of those as the substitute.
He averaged more than 20 disposals in 15 games for WAFL club East Fremantle and was part of the Sharks' losing grand final team last Sunday.
He battled to squeeze into a West Coast midfield that included established young players Scott Selwood, Luke Shuey, Andrew Gaff and Chris Masten as well as Daniel Kerr, Matt Priddis and Matt Rosa.
Neates, who made his debut in round seven against Essendon this season, played just that one senior game and suffered a horror run of injuries in his three years at the club.
Mascoulis and Papertalk have been delisted after just one year with the Eagles.
Nathan Schmook covers West Coast news for AFL.com.au. Follow him on Twitter: @AFL_Nathan
