"He threatened me a couple of times to make this decision," Johnson quipped Friday after signing a four-year contract to play for the Panthers.
Johnson, who negotiated the contract himself while his agent serves a one-year suspension, got a $19 million deal that includes a $5 million signing bonus.
"Was I unreasonable?" he asked general manager Marty Hurney.
"Apparently not!" Hurney fired back.
Johnson becomes the complement to Smith that the Panthers lacked last season during their run to the NFC Championship Game. Smith was their only big playmaker, and teams could clamp down on him to stop Carolina's offense.
Johnson called Smith "the most dominant force in the NFL at wide receiver" and said he was looking forward to lining up next to him.
"I didn't come here to catch 100 balls," Johnson said. "I came here because I feel Carolina is the team with the best chance to get to the Super Bowl."
Released last week by the Dallas Cowboys, Johnson rejected a bid from the New York Giants and also planned to meet with the Seahawks. But after coming to Charlotte on Thursday, he never made it to Seattle because the Panthers convinced him to stay.
"We have a wide receiver and a football player who is going to have a huge effect on this football team the next four years," Hurney said before handing Johnson his new No. 19 Panthers jersey.
Johnson said it doesn't bother him if quarterback Jake Delhomme considers Smith his No. 1 target.
"The only people who get caught up in No. 1 or No. 2 are the ones playing fantasy football," he said. "The only number that means anything is the number of [Super Bowl] rings you have on your finger.
"Steve is important to me and he's the reason I came here," he said. "And I'm important to him."
With Johnson on the field, defenses can't zero in on Smith because they'll know the Panthers have at least a second option. Carolina lacked that for most of the year because its running game took months to develop, and No. 2 receiver Keary Colbert had a big drop off from his outstanding rookie season.
Now Johnson takes over that No. 2 role, where he can also be used as a blocker to open up DeShaun Foster and the running game. Colbert, who had offseason ankle surgery to correct a problem that apparently bothered him most of last year, won't have as much pressure on him.
But the signing of Johnson is out of character for the Panthers, who have made a public effort to run a problem-free program since John Fox became head coach in 2002. After a series of off-the-field problems, including former wide receiver Rae Carruth's conviction in a murder-for-hire plot on his pregnant girlfriend, the team has avoided signing players with bad reputations.
Johnson left the New York Jets and Tampa Bay Buccaneers on bad terms. But his last two years with the Cowboys have been trouble-free under
disciplinarian Bill Parcells. Still, he couldn't avoid the questions about his character.
"How come everyone keeps signing me if I'm such a problem?" Johnson said. "I know I wouldn't sign Keyshawn for all this money if I'm a problem."
But he also said he has an image that's hard to shake.
"I'm Me-Shawn," he said, smiling at the nickname he inherited over the last 10 years in the league. "I'm fine with that."
Panthers officials talked to some of Johnson's former clubs and got positive reports.
"We knew we had a good player," Hurney said. "Everyone we talked to had something very good to say."