So it came as little surprise that Walker, after hitting the two biggest shots of the game to lift Boston to a 102-99 victory Tuesday over the Toronto Raptors in Game 2 of their Eastern Conference semifinal, was grinning from ear to ear in The Field House at the Walt Disney World Resort.
In his ninth NBA season, Walker finds himself in the second round of the NBA playoffs for the first time -- and now is two wins from a trip to the Eastern Conference finals.
"You know," Walker said when asked why he celebrated with a lap around the court as he pumped his fist, "you know what I've been through. Everybody knows what I've been through ... haven't been in the second round.
"And, a lot of times in my career, in games like that, it probably would have been a blowout. But for me to have these guys, who can step up and just make huge plays the way they did, man, it's special. And it's a great feeling to know guys got my back like that. I just really appreciate my teammates."
The "games like that" Walker was referring to was him shooting 2-for-14 through three quarters. During the first eight years of his career, when the guard was the sole force around which the Charlotte Hornets were built, such a performance would have sunk his team's chances of winning.
Instead, Walker now finds himself surrounded by an ensemble that can pick him up. For much of the game, support came from Jayson Tatum, who finished with 34 points -- including 14-for-14 from the free throw line -- to go with 8 rebounds and 6 assists.
But in the fourth quarter, Walker and Marcus Smart took over, scoring a combined 27 points on 9-of-10 shooting to outscore the Raptors by themselves and give the Celtics a 2-0 lead in this best-of-seven series.
The fireworks began with Smart, Boston's do-it-all guard, giving his best attempt at embodying the Human Torch over the first few minutes of the fourth quarter, hitting five consecutive 3-pointers help erase Toronto's eight-point lead.
Have a Marcus Smart in your life, it will be better 🍀— Vincent Poirier (@viinze_17P) September 2, 2020
Smart's final triple came with his legs flailing as he tried to draw a foul -- which he did. He then hit the free throw to give the Celtics the lead.
"That's just me," Smart said when asked where he gets his confidence. "Growing up I've always had confidence. That's just what it is. I believe in myself. I always have and I always will."
Smart finished 6-for-11 from 3-point range, and, coupled with his 5-for-9 showing in Game 1, is 11-for-20 in the series. It is an outburst reminiscent of Raptors guard Fred VanVleet in the 2019 Eastern Conference finals against the Milwaukee Bucks. Smart went 2-for-15 on 3-pointers against Philadelphia in the previous round; last year, VanVleet shot 1-for-14 from behind the arc against the Sixers.
"That's a pretty good comparison," Raptors coach Nick Nurse said. "I didn't think of that but that's a pretty good comparison. They obviously have a lot of firepower around and to have a wild card, I mean, listen, he's a great player and he's a veteran who has been around forever.
"But he is kind of a wild-card scorer for them and he's had two huge games for them."
Then, after Smart got the Celtics back in the game, Walker took them home. After struggling through three quarters, Walker went a perfect 4-for-4 in the fourth -- including a 3-pointer on the left wing with 2:24 remaining to double Boston's lead, then a step-back jumper from the right elbow with 41.6 seconds left.
Walker was the only Celtic to make a field goal inside the final five minutes, and the only Celtics player to score at all inside the final three, allowing Boston to have just enough to survive and put a stranglehold on the series.
"I've missed so many shots in my life," Walker said. "I have missed so many shots throughout my career. I'm never going to get down on myself. I'm going to find ways to help my teammates. I thought tonight, I thought I stayed solid defensively, which was most important.
"My teammates held it down. Smart came in, made some huge 3s, [Tatum] played well all game, a lot of guys had great contributions. And down the stretch, just staying confident.
"I work hard on my game. I thought I got great looks, and they weren't falling. It happens to the best of us. I just stayed aggressive, and just stayed within myself."
In the past, Walker had to do everything for his team to win. Now he just needs to make plays when it matters. It's a formula Boston has utilized throughout these playoffs -- where the Celtics are 6-0.
That's why Walker is, for the first time in his NBA career, in the middle of a deep playoff run. And with two more victories, the Celtics will be back in the Eastern Conference finals for a third time in four years.
"We have to continue to play desperate," Smart said. "Even though we're up, we have to play like we're down. We have to play games to win, not to lose. A lot of teams at this point, they play not to lose instead of just being who they are. For us, that's getting up into guys, playing great defense, and moving the ball on the offensive end."