(Associated Press)

The other day, Zac MacMath walked into the media room at PPL Park … wearing a worn-out T-shirt and form-fitting running shorts.

If the guy doesn’t feel at home, he does a good job hiding it.

In his first season as the Union’s starting goalkeeper, MacMath has played, spoken to the media, and communicated with his teammates like a savvy veteran. He’s played beyond his years, as a second-year pro. You could argue he's found his comfort zone.

No one -- not even MacMath -- is willing to sweep under the rug a couple of the head-scratching goals he's given up. A few times this season, he's made himself tall by making a step on the ball by racing from the goal line. And he's looked bad in the process. MacMath admits he misread the ball on which he gave up a goal last weekend in a win over New England, in which a 30-yard blast dipped more than once. But that's where MacMath has stood tall in the locker room, fielding judgmental questions from reporters without skipping a beat.

MacMath cites mental preparation as his biggest challenge this season, which has seen him post the fourth-most shutouts (five cleansheets) and the seventh-best goals-against average (1.18 GAA) among keepers with at least eight starts.

“I think the toughest part is mentally staying in every game,” MacMath said. “Every week, I know I’m the starter and I have to come to practice motivated and continue to work hard and learn from my mistakes and go into every game keeping my team in it.

“A lot of goalkeepers have different things they do. I try to keep my eyes on the ball and each half, in different increments, try to mentally focus and communicate with the team and keep my body warm.”

MacMath’s benefited from the strength of his backline, which features left back Gabriel Farfan, right back Sheanon Williams and centerbacks Carlos Valdes and Amobi Okugo. At times, he’s had Danny Califf – a veteran, and the Union’s former captain – at his disposal. But there have been other times when MacMath has had to cover for rookie Ray Gaddis, who’s gotten a number of spot starts.

And chances are, MacMath’s numbers will only improve whenBakary Soumare makes his debut. The 26-year-old centerback, Soumare – signed June 23 – is expected to play Saturday at Montreal, according to Union interim manager John Hackworth.