He said Friday on Fox Sports 1: "My guy that I would start the season with would be Sean Mannion. I've been saying that since last year. Give him a shot."
Dickerson added: "It's all about winning football games. You have a better chance of winning with Sean Mannion."
The 56-year-old Pro Football Hall of Fame inductee has been an outspoken critic of Goff for a while. He ripped his play following the preseason of his rookie campaign, telling Eric Edholm of Yahoo Sports last September:
"I gave [Goff] a flat-out D. He just didn't perform well in the preseason. I am just being honest. You might not like it. I don't care if it comes from me. I just think it's true.
"He didn't look prepared. And I think he tried to prepare. It's just fast. It moves faster. He didn't do a lot under center in college, and here in the pros the defenses move a lot more. I just don't think he's ready to play. That's not my call. It's just my opinion. You can't put him out there. You don't want to damage him."
Goff ended up making seven starts during his debut NFL season, and his lack of production in those games made Dickerson's words seem prophetic. He completed 54.6 percent of his throws for 1,089 yards with five touchdowns and seven interceptions en route to a miserable 63.6 passer rating.
Meanwhile, Mannion has attempted just 13 regular-season passes since the Rams selected him in the third round of the 2015 draft. He posted a 94.1 rating during the 2016 preseason but ended up third on the depth chart behind Goff and Case Keenum, who's now with the Minnesota Vikings.
Barring injury, it's hard to imagine anyone but Goff starting Week 1 against the Indianapolis Colts, though.