The Rams (4-5) scored only 139 points, ranking last in the league at that level. The Dolphins (5-4) won four games in a row.
Goff replaces Case Keenum, who collected 2169 air yards (19th place in the NFL). Keenum has nine touchdowns and 11 interceptions.
The Rams were unable to score a touchdown in three games: a curtain raiser (bleached 28-0 in San Francisco), then a 9-3 and 9-6 victory over the Seahawks and Jets.
Goff did not impress in the preparatory matches, but the Rams fans wanted him to be the starter for some time.
In the NCAA, Goff, who turned 22 in October, played for the Golden Bears of the University of California. He is from the San Francisco area.
Against the Dolphins, he will have to be wary of Cameron Wake and Ndamukong Suh, who have united their efforts for a dozen bags in 2016.