The Patriots will receive a 2024 sixth-round pick from the Raiders in the trade, while Herron and a 2024 seventh-round pick go to the Raiders.
The 6-foot-5, 305-pound Herron, who started 11 games under McDaniels in New England during the 2020 and 2021 seasons (including playoffs), projects as a possible starter at right tackle or as a top swing tackle.
While the teams had not announced the trade, McDaniels confirmed to reporters, saying general manager Dave Ziegler was presented with the "opportunity" to acquire Herron.
"A guy that we have some familiarity with, has played tackle in games, plenty of games, and has some versatility," McDaniels said. "Young player that's continuing to develop.
"We'll just let him come in and compete and acclimate to what we're doing and then see where it goes. But no expectations, other than just adding a player that we are familiar with that we feel like has some upside and looking forward to develop him."
The Raiders (0-2) lost projected starting right tackle Brandon Parker to a season-ending triceps injury in the opening week of the preseason, and 2021 first-round draft pick Alex Leatherwood was released at the end of training camp after struggling.
McDaniels and Ziegler -- formerly the Patriots' director of player personnel -- know Herron well, having worked with him closely after the Patriots selected him in the sixth round of the 2020 draft out of Wake Forest. They also saw him up close in August when the Patriots and Raiders practiced together before playing each other in the preseason finale.
Herron started six games as a rookie -- four at left tackle, one at right tackle and one as an eligible tight end. In 2021, he started two regular-season games at left tackle and two regular-season games at right tackle, and then started the Patriots' playoff loss to the Buffalo Bills at left tackle. He hasn't played in the Patriots' first two games this season.
In March 2021, Herron was honored as a hero by the Tempe (Arizona) Police Department for helping to stop an attempted sexual assault in an area park.