Andy Pettitte was back at Yankee Stadium on Thursday in his new role as an adviser, and the retired pitcher threw some batting practice before the Yankees’ 5-3 win over the Blue Jays.

But it’s what he has been doing with a certain struggling fellow left-hander that could yield more significant dividends than anything else, as the Yankees try to straighten out Carlos Rodon before the end of his disastrous first season in The Bronx.

And Pettitte said there are reasons for optimism — including in the bullpen session Rodon threw Thursday, as well as his previous two outings.

“He’s in a tough situation with the season he’s had and the injuries he’s had,’’ Pettitte said of Rodon. “Before the last road trip, I saw one of his pens that wasn’t quality,’’ Pettitte said. “He was all over the place. Then he went out in Boston and Pittsburgh and pitched well. That’s a step forward. I appreciate the work he’s put in.”

The work continued, even with the Yankees on the verge of being eliminated from the playoff race.

Rodon has dealt with back, forearm and hamstring woes, which have led to a 5.90 ERA that is actually down from a season-worst 6.60 thanks to his two most recent outings.

“He was so good [Thursday], you just want to see that and let him settle in,’’ Pettitte said of the bullpen session. “My message to him has been, ‘Let’s stay healthy, get out there and get some reps.’ ”

Despite Rodon’s lack of results, Pettitte has seen some similarities between himself and the 30-year-old, who hasn’t shied away from being critical of his performance.

“He wants to be great,’’ Pettitte said. “We know how this place is. It’s a tough place to play. I came up here, and it was difficult for me. I wanted to do so well, and I love that part of him. He’s hard on himself. I tell everyone that comes here, ‘Wear it.’ If you didn’t pitch well, say you didn’t pitch well and take it out of everybody’s hands. He’s done that.”

Rodon will try to begin to change the trajectory of his Yankees career Saturday against Arizona.

In six starts at the Stadium, Rodon has a 6.59 ERA, compared to an also-rough 5.28 in six starts on the road.

“He’s been struggling through it,’’ Pettitte said. “It’s no fun, and it’s hard to go out there when you don’t have your best stuff. But I know he’s excited and wants to get more good outings under his belt. “

Pettitte has tried to help Rodon get his confidence back.

“When you’re not seeing results, who’s not shaken by that?” Pettitte said. “I just try to build him up and try to be positive.”

Against the Red Sox and Pirates, Rodon allowed four runs over 11 ²/₃ innings for a 3.08 ERA.

He also set season-highs with strikeouts in both starts.

“He needs to toe the rubber and get comfortable with his mech and find whatever he needs to find,’’ Pettitte said. “He obviously found something over his last couple starts, and things have ticked up. I’m just patting him on the butt. That’s all you can do. This game is hard, and sometimes, it gets the best of you.”

And the poor results undoubtedly sapped Rodon of some of his confidence.

Saturday will be his final start in The Bronx this year, and Pettitte knows how quickly perceptions can change.

“If he goes out there, pitches well and strikes out 10, he’ll get cheered,’’ Pettitte said. “But I told him not to worry about all that. He needs to go out there and keep his blinders on. That’s hard to do, but if he takes care of his business, he’s gonna be good.”