Earlier this offseason, the Raiders signed quarterback Jimmy Garoppolo to a three-year, $72.75 million contract on March 17. Las Vegas also has the No. 7 pick in this month's draft.
Hoyer was released by the New England Patriots prior to the start of free agency.
Hoyer started one game in 2022, a Week 4 overtime loss to the Green Bay Packers, after Mac Jones had suffered a high ankle sprain the week before. But Hoyer was knocked out of the game with a concussion at the end of the second series. He was 5-of-6 for 37 yards at the time of the injury.
The 37-year-old Hoyer remained on injured reserve for the rest of the season.
He had one year remaining on his contract, which included $1.4 million in guaranteed money for 2023.
The Raiders also added a former Patriots player to the staff Tuesday in Danny Amendola, who was given the title of coaching assistant/returners.
McDaniels said he didn't have a coach for the return specialists last season.
"It's a valuable guy, if you can find the right one," McDaniels told ESPN. "He has done it and done it at a high level. He will help our guys."
Amendola spent five of his 13 NFL seasons with New England (2013-17) when Raiders coach Josh McDaniels was the Patriots' offensive coordinator. During that period, Amendola had 230 catches for 2,383 yards and 12 touchdowns. He also returned 85 punts for 773 yards (averaging 9.1 yards) and 34 kickoffs for 799 yards (averaging 23.5 yards) with New England.
His presence also might help Raiders slot receiver Hunter Renfrow continue his adjustment to McDaniels' system. Renfrow, coming off a Pro Bowl season, suffered concussion and oblique injuries and had career lows in catches (36), receiving yards (330) and TD catches (2). He has also returned 70 punts for 680 yards (9.7 average) in his four-year career.
McDaniels said he was looking forward to a healthy season by Renfrow and compared him to the likes of Amendola, Wes Welker and Julian Edelman.
"I mean, obviously, he was a big reason I was excited about being here," McDaniels said of Renfrow at the recent NFL owners meetings. "I've had a long history [with] these kind of guys, you know, that I've had a chance to work with and was super excited and still, I'm super excited about."
ESPN's Paul Gutierrez and Mike Reiss contributed to this report.