Stewart stood up for his rookie driver on Saturday at Indianapolis Motor Speedway when questioned about Patrick recently asking him whether she was meeting his expectations.
The owner of Stewart-Haas Racing referenced a recent comment made by Petty, a former driver and NASCAR analyst for Fox Sports and TNT, about Patrick not being a racecar driver and "I don't think she's ever going to be a racecar driver."
"When Kyle Petty said the stuff he did, it was way out of line and very inappropriate," Stewart said during qualifying for Sunday's Brickyard 400. "There's a lot of factors that go into it. Some of the finishes we know she should have had have been pit-crew related, some of them are days that Ryan [Newman] and myself and we all struggle. It's not just her.
"When somebody like Kyle beats you up like that, you take it to heart. She's somebody who wants to do things the right way. She works at it. It's a scenario where somebody has to tell you, 'You are doing the right thing and disregard what one person says.' "
Patrick is 27th in points with one top-10 finish -- an eighth in the Daytona 500 where she started on the pole. Her average starting position has been 30.7 and her average finish 25.6.
But Stewart said he is proud of what Patrick has accomplished since leaving the IndyCar Series after the 2011 season to pursue a full-time career in NASCAR.
That she asked if she was meeting expectations showed him her desire to succeed.
"She doesn't sit there and pout about it," Stewart said. "She's like, 'OK, if something is not right, what do I do to make it better?' She's got the right mindset, she does the right things, she asks the right questions.
"I've said it from Day One, she does everything right in my opinion."
Patrick is looking forward to her debut in a Cup car at IMS, where she finished third in the 2009 Indianapolis 500 and had six top 10s in seven 500s.
"They are equally challenging," she said of running here in a stock car versus IndyCar. "When you get flat [out] in an IndyCar, its generally fairly comfortable. Building up to that is grab your gonads and go for it.
"It's similar in a stock car. I think Newman said, 'Go flat [out] 'til you see God and then lift.' "
Patrick hasn't gotten completely comfortable here in a stock car. She qualified 33rd and has been slow in practice.
But nothing she's done has given her boss cause to lose faith in her.
"To some degree that's the real question, is what are the expectations of me," Patrick said of her conversation with Stewart two weeks ago at New Hampshire Motor Speedway. "Do you think I am supposed to be in the top 20 and top 15 all the time? Or am I not?
"He said, 'If I saw there being an issue, or something that stood out as a problem or an area you needed to work on, I would have come to you already, but I don't see it. And every time I'm behind you, you are doing the right thing.'
"He said we have to work on the cars and make them better, and he thinks I'm doing a good job. That's the boss ... so."