After waiting patiently for six weeks to make his season debut, Union centerback Mark McKenzie probably didn’t expect to take the field in quite the way he did. But he knew he had to be ready no matter when the opportunity came. And when Auston Trusty was sent off during last Saturday’s loss at the Los Angeles Galaxy, McKenzie knew it was time. He duly came off the bench in the 78th minute, and this Saturday will start against the Montreal Impact at Talen Energy Stadium (1 p.m., PHL17).

“You always prepare as if you’re about to go in, so that way once you get in the game you just go and try to find your feet, try to find the rhythm of the game,” McKenzie, who started 18 games as a rookie last season, said after Wednesday’s practice. "Once you get into the game, it’s just playing, doing the simple things.”

Before last Saturday, McKenzie’s only game action of any kind all year was an appearance with Bethlehem Steel on March 24. There were mitigating factors, including an ankle injury in preseason and a concussion in early March. But if the wait to return to action for the Union was difficult, he did a good job of not showing it.

“I mean, look, it’s a long season, so, you know, you prepare every day and grind every day as if you’re going into the game, so when your name is called it’s not a news flash,” he said.

That same consistent, humble work ethic fueled his rise to prominence as a teenager. For all of McKenzie’s skill on the field, the Union academy product’s mental strength is also a great asset.

“It’s a game that we try to over-complicate sometimes, but connect your passes, win your duels, win your battles, and the rest will kind of handle itself,” he said.

“The rest” in McKenzie’s case also includes the countdown to the under-20 World Cup, and his potential to be the U.S. team captain. U.S. coach Tab Ramos will name his 21-player team by May 3, ahead of the tournament’s kickoff on May 23.

The back-and-forth of recent months between Ramos and Union sporting director Ernst Tanner over whether the Union will let McKenzie go to the World Cup seems to have cooled off at this point, and perhaps it was a bit overblown in the first place. Asked about the state of things, McKenzie didn’t answer directly but gave a laugh that signaled he knows what’s going on and isn’t worried.

“I’m good. Right now I’m focused on playing here,” he said. “We’ve got a game against Montreal coming up. Yeah, the World Cup is coming up in a few weeks, but at the same time, I’ve got my first start here, so I’m just kind of focused on that and helping the team any way I can.”