When Jeff Green’s name is announced with the Boston Celtics’ starters at TD Garden, he shoots from his seat and slaps five through two lines of teammates until he reaches Jason Terry. At that point, Green presses his fists against his sternum and pulls them apart, pantomiming tearing open his chest. Terry, who sits in the adjacent locker room stall, has given Green the nickname “Iron Man,” after the comic-book superhero with a hole in his chest and shrapnel near his heart. Green does the same chest-ripping gesture after an emphatic dunk or any other highlight-worthy play, reminders that while Green might not save lives and destroy bad guys like the make-believe Tony Stark, he remains on a spectacular journey nearly 16 months after surgery to fix an aortic aneurysm. “You know, I’m blessed,” said Green, 26. “Last year, I missed the whole season, dealing with surgery on my heart. That’s not something you hear too often in this league and it’s not something a guy my age and only a couple of years in the league wanted to hear. But to be in position to play in every game this year, in addition to these playoffs, and the confidence that I’ve played the game has been better than ever. I’m still a work in progress, but I’m in a great position.” Green, the former standout at Georgetown University and Hyattsville’s Northwestern High, has been the Celtics’ leading scorer in their playoff series against the New York Knicks, averaging 19 points through the first three games. New York has dominated the Celtics and has an opportunity to complete a sweep on Sunday at 1 p.m., but Green isn’t willing to surrender anything. “They haven’t won it yet. As long as we’re still playing, we have a chance,” Green said, though no NBA team has ever come back from a 3-0 deficit to win a playoff series. Green has been counted out before. Each whirling drive and turnaround jumper is a testament to how far he has come since undergoing five hours of surgery on Jan. 9, 2012. He remembers having to press a pillow against his chest to limit the pain whenever he coughed or sneezed, and the feeling of accomplishment when he was finally able to take 10 steps without gasping for air. Green readily admits that he hasn’t fully recovered and that he continues to grapple with his conditioning. While he must pay closer attention to his body, he is also proud to flaunt it. Though he wears a customized, padded tank top beneath his uniform to protect himself during games, Green will walk around shirtless after practice, exposing the nearly foot-long scar down the middle of his chest. “It’s me. The new me,” Green said proudly. “Something that shows what I’ve been through. It shows my character. God puts you in positions to succeed and he humbles you. And that scar humbled me and made me appreciate life a lot more, because it was almost taken from me. And the game I love was almost taken from me.” Green arrived in Boston in early December 2011 to take a routine physical and sign a one-year qualifying offer worth $9 million to return to the team that acquired him for fan favorite Kendrick Perkins 10 months before. He barely had time to celebrate his new deal before he learned that he had failed his stress test and that a rapidly expanding aortic root and a leaking aortic valve required surgery.