Brown will receive a new three-year deal worth up to $54.125 million from the Raiders, with $30.125 million guaranteed, the source said. He previously had three years and $38.9 million left on his contract with the Steelers, with none of the money guaranteed.
Brown first indicated on his Instagram account late Saturday night that he was heading to Oakland.
Trades are not official until the new league year begins Wednesday.
For the Raiders, the addition of Brown provides an explosive deep threat for quarterback Derek Carr that coach Jon Gruden and the rebuilding team desperately need.
The Raiders, who have had one winning season and one playoff appearance since the 2002 season, had the 18th-ranked passing game in the NFL last season, averaging 234.4 yards, and their 19 receiving touchdowns were tied for 24th. Jordy Nelson led Oakland receivers last season with 63 receptions for 739 yards and three TDs.
Brown recorded Hall of Fame-type production in Pittsburgh with 834 receptions, 11,207 yards and 74 touchdown catches in nine years, including an NFL-record six consecutive 100-catch seasons. But a frayed relationship between the player and team overshadowed the gaudy numbers, and a divorce became inevitable.
When the Steelers began entertaining a trade in January, they believed Brown’s market would be strong, with one NFL general manager saying the Steelers would eye a first-round pick in any deal.
The market was strong enough that the team could deal Brown, who turns 31 in July, before free agency started. The Steelers marked Friday as an artificial deadline for a trade after several teams — including the Raiders, Washington Redskins and Tennessee Titans, according to Schefter — showed interest during the NFL scouting combine.
Without Brown, JuJu Smith-Schuster will be Pittsburgh’s No. 1 receiver and the focal point of the offense in 2019. He recorded a team-high 111 catches and earned his first Pro Bowl bid last season. The depth chart behind him, however, isn’t so clear-cut.
James Washington, a second-round pick in 2018, has obvious talent but struggled to find a rhythm as a rookie, though he did encourage with a pair of 60-plus-yard performances late in the year. Slot receiver Ryan Switzer, who made an impact with 36 catches for 253 yards in his first season in Pittsburgh, is the only other core veteran wideout under contract. Three reserves — Darrius Heyward-Bey, Justin Hunter and Eli Rogers — are unrestricted free agents.
The Steelers are among the league’s most successful teams at identifying receiver talent in the draft and could select a Day 2 wideout for the second consecutive year to help replace Brown. They can also expand the passing game duties of tight end Vance McDonald and running backs James Conner and Jaylen Samuels.
Information from ESPN’s Jeremy Fowler and Paul Gutierrez was used in this report.