The moves to get rid of Heyward-Bey and Huff leave just three of Oakland's former first-round picks on the roster with linebacker Rolando McClain also expected to be released this off-season.
The lack of production from high draft picks is a major reason why the Raiders have lost the second-most games in the NFL over the past 10 seasons with 111. Oakland has failed to post a winning record or make the playoffs during that stint.
Late owner Al Davis' death in October 2011 led to drastic changes in the organization with Reggie McKenzie taking over as general manager and hiring Dennis Allen as coach. The team went 4-12 under the new regime last season as McKenzie began a major roster overhaul that is still ongoing.
While Heyward-Bey has been mostly a disappointment in his career, the move to get rid of Huff comes as some surprise since he was the team's most consistent defensive back last season.
"The Raiders would like to thank Michael Huff and Darrius Heyward-Bey for their contributions to our organization, both on the field and especially in our community, over the last several years," the team said in a statement. "We sincerely wish them well in their future endeavours."
Heyward-Bey was one of Davis' most controversial draft picks in 2009 when he was selected seventh overall based on his blazing speed ahead of more productive college receivers like Michael Crabtree, Percy Harvin and Jeremy Maclin.
After having just nine catches as a rookie and 26 in his second year, Heyward-Bey showed signs of emerging in 2011 when he caught 64 passes for 975 yards and four touchdowns. But he regressed a bit last season when he had 41 catches for 606 yards and five scores.
Heyward-Bey had a base salary of about $7.7 million for 2013 and the Raiders determined his production was not worth that lofty salary.
The move leaves the Raiders with little experience at receiver with two-year pro Denarius Moore the most seasoned on the roster. Former starter Jacoby Ford, who missed last year with a foot injury, is also expected to be back next season.
Huff was drafted seventh overall in 2006 and struggled initially at safety. But his play improved in recent years and he signed a four-year, $32 million deal to stay in Oakland in 2011.
Huff played mostly at cornerback for the Raiders last season because of injuries but was being expected to return to safety this year. Oakland is negotiating with free agent safety Mike Mitchell to keep him on the team.
Huff has 11 career interceptions in 108 career games.
Tollefson, a two-time Super Bowl winner with the New York Giants, signed a two-year deal to return to the Raiders last off-season but was a disappointment in his second stint with the team.
Besides McClain, the other first-round picks still in Oakland are kicker Sebastian Janikowski and running back Darren McFadden. Oakland has the third pick this year, its first first-rounder since 2010.
Adams was one of the new players added last season when he was claimed off waivers from Seattle before the start of the season. Oakland signed him to a $630,000 deal before he became a restricted free agent.
Adams played sparingly early last season on defence before getting his chance because of injuries. He intercepted two passes, including one against Denver's Peyton Manning, and is currently the most experienced cornerback on the roster.
According to STATS LLC, Adams was targeted just 13 times in coverage last season, allowing seven catches for 109 yards and one touchdown.
Adams also returned punts last season, averaging 5.6 yards on 25 returns with two lost fumbles. But Oakland is hoping Ford will be healthy next season and will take over that role.
Adams was originally drafted in the seventh round by San Francisco in 2010 out of South Carolina State. He played 22 games as a reserve his first two seasons with the 49ers, New England and Seattle.
Also, Cleveland outside linebacker Kaluka Maiava is scheduled to visit the Raiders this week. Maiava started 13 games last season with 30 solo tackles, two sacks, two forced fumbles and three passes defenced.
Maiava has played 50 games over four seasons with the Browns after being a fourth-round pick out of Southern California. The Raiders are looking for help at linebacker with McClain not expected back and starting outside linebacker Philip Wheeler likely to leave as an unrestricted free agent.