The move came three days after Oakland placed Whalen on injured reserve due to turf toe. The newspaper, citing a source, reported that the Raiders reached a four-week injury settlement with the team.
If Whalen does sign not with another club, he will be eligible to re-sign with Oakland in Week 7.
Whalen signed with the Raiders in March after spending last season with the Baltimore Ravens. In 14 games with the Ravens, including two starts, Whalen had only four receptions for 23 yards.
An undrafted free agent out of Stanford, Whalen initially signed with the Indianapolis Colts in 2012 and spent his first season on injured reserve.
The 28-year-old Whalen had his best season in 2013 with the Colts. He appeared in nine games and made three starts while setting career highs with 24 receptions for 259 yards and two touchdowns.
In six seasons with the Colts, Chargers and Ravens, the 5-foot-11, 190-pound Whalen has appeared in 43 games (three starts) and has 51 catches for 532 yards and three touchdowns.