"That didn't happen," Mornhinweg said in a statement released by the Ravens. "Never said that."
Former NFL general manager Mike Lombardi said on The GM Shuffle podcast Monday that Mornhinweg was not a believer in Jackson as a quarterback. According to Lombardi, Mornhinweg asked his coaching staff, "When are we gonna move him to receiver?"
Mornhinweg denied that he suggested a position change for Jackson, who is now a leading candidate for NFL MVP.
"My thoughts before the draft, and even more when we started working with Lamar, was that this young man was going to be a special quarterback," Mornhinweg said. "Very early we saw that along with all of his throwing and escape abilities, he reads the field as well as any young quarterback I ever worked with."
Mornhinweg was the Ravens' playcaller during Jackson's rookie season. Baltimore promoted Greg Roman to offensive coordinator after the season, and Mornhinweg declined to remain on the coaching staff.
"Organizationally, we were on the same page with Lamar, and I thought Ozzie [Newsome] and Eric [DeCosta] did a great job to take him where we did," Ravens coach John Harbaugh said. "Marty was excited from the beginning to coach Lamar and was instrumental in helping him progress through his rookie season."
Jackson has led the Ravens (8-2) to their best start in seven years. He ranks No. 4 in the NFL with a 106.3 passer rating and No. 10 in the league with 788 rushing yards.
In Sunday's 41-7 win over the Houston Texans, Jackson became the first player in Ravens franchise history to produce multiple games with four or more touchdown passes in a single season.