Brian Wiese couldn’t believe he was talking to a high school kid.

When the Georgetown men’s soccer coach was recruiting Keegan Rosenberry, the two would sometimes have long phone conversations. And when those calls ended, Wiese would often marvel at what he heard on the other end of the line.

“You get off the phone with him and you’re like, ‘I think that was him and not his dad,’” Wiese says today with a laugh. “He’s an old man in a young man’s body.”

That uncommon wisdom and maturity was a major selling point for Wiese. It was also why the Hoyas coach knew Rosenberry could handle a move from midfield to fullback in just the second game of his freshman season at Georgetown … and why he wasn’t surprised to see him excel so much in that position after being taken No. 3 overall by the Philadelphia Union in the 2016 MLS SuperDraft (considered a reach by many pundits but not to him) … and why, most importantly, he believes Rosenberry’s selection for Thursday’s AT&T MLS All-Star Game (7:30 pm ET; ESPN and UniMás in US; TSN and RDS in Canada) is only the first rung in his ladder to stardom.

“I think he’s the perfect person to have early success in his career because he’s mature enough to handle it and not have it affect who he is and how he trains and plays,” Wiese says. “If anything, it will just continue to motivate him to prove he’s worthy of all of the accolades.”

Anyone who knows Rosenberry would certainly agree that the rookie doesn’t seem to be fazed by much. He showed that from the very beginning of the season when he got a surprise start in Philly’s 2016 opener at Western Conference power FC Dallas and again in his ninth MLS game when he made several memorable defensive plays in 1v1 battles with LA Galaxy stars Robbie Keane and Giovani dos Santos

So you can be sure he’ll be anything but starstruck when he greets his fellow MLS All-Stars this week in San Jose and then lines up against English Premier League power Arsenal on Thursday. But, as one of only two rookies on the All-Star team, that doesn’t mean he won’t try to be a sponge as well.

“I’m not going to be the guy trying to talk to everyone and strike up conversations with all the big-time guys,” Rosenberry says. “But just being in and around it and going to training is something I’m excited for, just to see how these guys carry themselves.”

All-Star: Union rookie Keegan Rosenberry an "old man in a young man's body" -

Rosenberry also knows the game itself could be an important showcase for him. Although he’s tied for second in the league in minutes played, the only rookie to play every possible minute for his team this season, the right back admitted that he doesn’t “think too many people go out of their way to watch Philadelphia play.” And so the chance to play in a marquee event on national television is a unique one that he’s eager to rise to the occasion for — even if he knows he must stay grounded for it at the same time.

That’s the same approach he’s taken as he’s heard the chatter about being in the mix for earning the MLS Rookie of the Year award and, perhaps, a United States national team call-up in the near future.

“I think it’s the same as playing against big stars,” Rosenberry says. “The only way to continue to hear those kind of accolades and praise and compliments is if you to continue to do what you’re doing. So I do my best not to put too much thought into it. You get some jokes from the guys on the team and my friends and stuff, but I do my best to shrug it off and say, ‘Thank you,’ and be humble about it.”

Gentle ribbing aside, his friends and teammates will certainly be tuning in for Thursday’s All-Star game to watch him rub shoulders with some of the world’s biggest stars. So will his old college coach, who expects to see the same kind of poise Rosenberry showed from his days at Georgetown when he played against the likes of the LA Galaxy and the Argentina national team in scrimmages.

“It helps him to lose the star-gazing that a lot of guys might otherwise have,” Wiese says. “I think he’s always been built that way. I don’t think he’ll ever be intimidated by anyone he’ll step on the field with. That’s just his nature. I think he’ll love it. I think he’ll appreciate it. But he won’t ever say, ‘Boy, I can’t handle it.’”

The Georgetown coach, who’s sent several players to the pros during his 11 years at the Hoyas’ helm, didn’t know for sure that would be the case when he decided to slot Rosenberry into the starting lineup for the second game of the 2012 season. But he did know that it was “clear to us he was going to be the answer at the right back position” because of his “rare combination of being a really good athlete and having a blue-collar work rate.” 

Rosenberry, who shined as a central midfielder in high school at Lancaster Mennonite, didn’t fight the decision because he knew it was the only way to get onto the field due to the Hoyas’ crowded midfield. If anything, he saw it as a “new challenge” and was encouraged when Wiese told him how Georgetown fullbacks have to be the team’s most complete players by combining toughness, athleticism, speed, fitness and technical ability — all attributes he either had or worked tirelessly to develop.

“And by the end of his freshman year, he was as good a fullback as I’ve been around,” says Wiese, who kept Rosenberry in that spot for the next three years after riding him to the 2012 national championship game. “It became too hard to move him. And to his credit, he kept evolving as a player every year in that position for us. And the question then became how he would translate from the college level to the pro level. And the next question is if the US gives him the opportunity with the full national team how he’d handle that next step.

“But Keegan is one of those guys that if you’ve been around him long enough, you’re saying, ‘Yeah, he’ll handle it.’ He’s handled everything else in his life pretty well so far.”

Rosenberry says he’s not yet heard anything from Jurgen Klinsmann or anyone else from the US national team. But he believes that if he continues to play every minute of every MLS game, and helps lead the Union into the playoffs this year, his chance to put on his country’s colors could perhaps be on the horizon.

A good performance in Thursday’s All-Star game couldn’t hurt, either.

“The sooner it comes, the better,” Rosenberry says. “But it’s not something I can control. I can only continue to play my best.”