Adam Schefter of ESPN added that the trade is done and draft picks are involved.
Switzer spent last year with the Dallas Cowboys, but the team traded him to Oakland in April in exchange for defensive end Jihad Ward. About four months later, it appears as though he is on the move again.
The 23-year-old was a fourth-round pick in the 2017 draft, but he played sparingly on offense in his first year, finishing with just six catches for 41 yards.
Switzer made a much bigger impact on special teams, where he averaged 25 yards per kick return and 8.8 yards per punt return, returning one for a touchdown.
While he seemed destined for a similar role with the Raiders, he apparently didn't impress the coaching staff while returning two punts for negative-one yards against the Green Bay Packers in Friday's preseason game. It's looking like Dwayne Harris will take on that role.
He also didn't make an impact on offense in a game in which 13 different players were targeted with at least one pass.
This likely factored into his trade to the Steelers, a team that is even more loaded in the receiver room, with Antonio Brown, JuJu Smith-Schuster and rookie James Washington.
Still, Switzer can be valuable once again in the return game while providing extra rest for stars like Brown and Smith-Schuster.