Bradford signed with Arizona as a free agent in March and received a $10 million signing bonus, about $2.5 million in base salary and another $1 million in playing-time bonuses for a total of $13.5 million.
He was scheduled to earn a total of $5 million in base salary in 2018 while being eligible for a $312,500 roster bonus for each game he was active. He also had an option for 2019 that would have been worth a maximum of $20 million. Any team that claims Bradford off waivers will inherit the 30-year-old's Cardinals contract.
The former Heisman Trophy winner started the Cardinals' first three games this season, but after losing the opening two and throwing two interceptions in Week 3, he was replaced by rookie Josh Rosen at the end of the defeat to Chicago.
Bradford completed 62.5 percent of his passes for 400 yards, two touchdowns and four interceptions in his nearly three games with Arizona (2-6), but he has been inactive since Week 4, which cost him -- and thus saved the Cardinals -- $1,562,500.
Bradford, who tore his left ACL in 2013 and '14, entered this season coming off another knee injury. He aggravated the knee in Week 1 last season with the Minnesota Vikings, missed the next three weeks and returned in Week 5 but was pulled before halftime.
Bradford missed the rest of the season, ending it on injured reserve, and he had his left knee scoped by renowned orthopedist Dr. James Andrews in early November. He repeatedly said his knee was healthy this season, but statistics showed that Bradford wasn't getting much pressure after the snap but was in a hurry to throw.
His average time in the pocket was 2.02 seconds per play, the third-shortest in the NFL, and he averaged 2.51 seconds before throwing a pass, the sixth-fastest rate in the league.
He was under pressure on 27.6 percent of his dropbacks, about an average number this season across the league, according to ESPN Stats & Information data. He was blitzed only 11 times -- or on 12.6 percent of his dropbacks, which was the lowest rate in the NFL -- and hit eight times and sacked six.
Also Saturday, Arizona placed offensive lineman John Wetzel on injured reserve with a neck injury.