CHARLOTTE, N.C. -- The Carolina Panthers' second-ranked defense can't get a nickname to stick, but coach Ron Rivera has one that won't go away no matter how much he'd like it to: Riverboat Ron.

Rivera was given the nickname after showing the instincts of a riverboat gambler when he successfully went for it on fourth-and-1 twice on the first series of a 35-10 victory at Minnesota on Oct. 13.

This image of Panthers coach Ron Rivera as a riverboat gambler took on a life of its own Monday night when Rivera's daughter, Courtney, posted it on Instagram. Courtesy of Jim Kennedy

The nickname took on a new life Monday when Jim Kennedy, a graphic artist from Raleigh, N.C., posted online a picture of Rivera as a riverboat gambler.

Rivera is portrayed wearing dark sunglasses, a black Panthers cowboy hat and a Panthers blue jacket with a black vest and a tie. In one hand he is holding a cigar and the other poker cards. In the background is a picture of Bank of America Stadium and the words Riverboat Ron.

Kennedy initially posted the picture to a Panthers' fan page. It exploded Monday night when Rivera's daughter, Courtney, posted it on Instagram and it later turned into a Twitter post.

Kennedy said he designed the picture after hearing friends refer to Rivera as "Riverboat" during Sunday's 10-9 victory at San Francisco that extended Carolina's winning streak to five.

"It's really nice, exciting how something like this I did for fun real quick got spread all over the Internet," Kennedy said. "It's cool Rivera's daughter saw it. That means he may see it."

Rivera had no idea his daughter posted the picture until told during his Wednesday news conference.

"Oh, that's not fair now," Rivera said as he looked at his cellphone to reread a text message from his daughter that made more sense. "I'm going to talk to her."

Rivera wasn't a gambler before this season. Only one NFL coach had gambled less on fourth down than him since 2011, and that was former Carolina coach John Fox.

Rivera changed his philosophy after being criticized for not gambling in a 24-23 loss to Buffalo in Week 2. With a three-point lead and just under two minutes left, Rivera elected to go for a short field goal to give the Panthers a six-point lead.

That put the Bills in position of having to score a touchdown to win, which they did with two seconds left.

Rivera said he decided on the bus ride to the airport afterward that he needed to be more aggressive and show more faith in his offense in those situations.

Since then, the Panthers (6-3) have converted 5 of 7 fourth-and-1 plays.

"The thing I really like is the guys have said to me they appreciate me showing faith in who we are as a football team," Rivera said.

But Rivera doesn't particularly like the nickname, saying the calls are well thought out and calculated risks. Asked how many of his players call him "Riverboat," Rivera smiled and said, "Unfortunately, too many of them."

Left tackle Jordan Gross is as guilty as anybody. He used the nickname on his coach in the weight room Wednesday, making him blush.

Not all players are so daring.

"I don't think you want to tease our head coach," quarterback Cam Newton said. "That's not a good method of flattery."

Newton paused to admit he wasn't familiar with the nickname. When it was explained to him, he said, "Oh. I heard a couple of people call him Chico. That has been something that has followed him since Chicago."

Rivera, a former linebacker for the Chicago Bears, was given that nickname when he became the first American of Puerto Rican descent to play in the NFL.

"I don't think any player would say, 'Hey, Coach Riverboat,'" Newton said. "No, I don't think even you. You would be getting a letter, a memo, by Mr. [general manager] Dave Gettleman with that."

Defensive end Greg Hardy agreed.

"You call your boss a name," he said. "I want to keep my job, so no. Ron. Riveting Ron."