But Gettleman wouldn't say whether the Panthers would attempt to negotiate a long-term deal with Newton, the first pick of the 2011 draft, or pick up a fifth-year option on his current contract.
"He proved it to me," Gettleman said Tuesday in his first public comments to the media since training camp. "He proved it this year. He flat proved it."
Prior to the season, Gettleman said it was time for Newton to win after 6-10 and 7-9 seasons. Asked if the former Heisman Trophy winner was his franchise quarterback after Carolina made its first trip to the playoffs since 2008, Gettleman didn't hesitate to say yes.
"No seven-second pause was there?" Gettleman said. "Yes, he is."
The Panthers have until May 3 to pick up the fifth-year option, which would be similar to a franchise tag. Newton would be entitled to the average salary of the league's 10 highest-paid quarterbacks. He is in the third year of a four-year, $22 million deal.
"I don't talk contracts," Gettleman said. "I can't work in a vacuum where you work year to year. We are cap challenged, and that's not going away anytime soon. In the next month, we are going to thoughtfully look at next year and a three-year projection and five-year projection.
"I know we're only as good as our most recent game. I get that. But the bottom line is you can't work year to year. There is no way to create continuity. You have to identify the core and keep the core."
Gettleman took over a team last season that was more than $16 million over the salary cap. Through cuts and contract renegotiations, the Panthers are now more than $17 million under the cap.
Still, Gettleman said the cap remains a problem and will be through 2015.
"The good lord willing and the creek don't rise, we'll be out of it in two years," he said.
But Gettleman's situation is better than it was when he took over in February. He likes the core of Newton, middle linebacker Luke Kuechly and other young players who are under contract.
He'll spend the next month evaluating and deciding how to move forward with the 21 players who will become unrestricted free agents. Eight of those are starters, including defensive end Greg Hardy and left tackle Jordan Gross.
Hardy was second in the NFL in sacks with 15, and Gross anchored a line that was plagued by injuries early in the season.
Gettleman wouldn't commit to whether either will be with the team in 2014, saying he didn't want to make any snap decisions or statements with Sunday's 23-10 loss to San Francisco in an NFC divisional game still fresh.
"The biggest mistake you can make is make emotional decisions," Gettleman said. "We have to make business decisions, and it takes time. Until then, I'm not going to say who we're signing and who we're not signing and what our strengths are and what our weaknesses are."
Hardy has said for months that he would give Carolina a hometown discount if it was within reason. He recently said he wouldn't mind the franchise tag if that helped the Panthers financially. On Monday, Hardy said his preference was to remain with Carolina but added he would get want he wanted.