Jack McGlynn strode to the spot during the third round of a penalty kick shootout Sunday night, took a deep breath and stutter-stepped before burying his attempt and helping send the Philadelphia Union past Nashville SC to next weekend's Eastern Conference Final.

The baby-faced assassin smiled as he turned toward teammates at midfield, and with Subaru Park roaring all around him, did the “ice in my veins” celebration.

McGlynn looked like he’d been here before, even though he might get carded trying to get into an R-rated movie.

The 18-year-old homegrown asked to be among the Union’s penalty takers, which speaks to his resolve, according to Philadelphia coach Jim Curtin.

“For him to step up in that moment, there's a word for it that I won't use on the press conference, but he has brass ones,” Curtin said. “He stepped up in a big spot in a full stadium in an elimination game and calmly goes about it like it's nothing.”

McGlynn, who joined Jack Elliott as the Union's two successful PK takers, came on for Jamiro Monteiro in the 106th minute for his second substitute appearance of the Audi 2021 MLS Cup Playoffs. The midfielder made 19 appearances in his rookie season, with seven starts.

And while it’s proven difficult to crack the starting lineup, especially in the Union’s loaded midfield, the kid from Queens, N.Y. has impressed Curtin.

“Jack McGlynn has a huge future. I know that a lot of people haven't seen him play as much as maybe he would like or even the league would like – the same goes for Quinn Sullivan, the same goes for Paxten Aaronson,” Curtin said. “But these kids are going to be really, really special. And a night like tonight only builds confidence for him.”

Andre Blake was Philly's other PK hero, saving two of Nashville’s four unsuccessful attempts. That was somewhat expected from the two-time Allstate Goalkeeper of the Year. But the Jamaican international was impressed with McGlynn’s composure in a big moment.

“He's a great player. He's humble, he listens and he wants to learn. He's very technical. We had no doubt in him,” Blake said of the US U-20 international. “He shoots every time in training so we know how well he hits the ball and we know that he's confident. We had no doubt putting him in the top five and he went out there and executed. That's big-time for us and definitely does a lot for his confidence going forward as well.”