In the Union's first 10 MLS games he played exactly one minute.
Then he saw 25 minutes in a 1-0 loss at Toronto on May 26. His biggest moment came in a non-MLS event, when Hoppenot scored the game-winner in the 95th minute of a 2-1 overtime victory over host D.C. United in the U.S. Open Cup.
"That was an incredible feeling and kind of like a dream come true," he said.
Despite his heroics, Hoppenot wasn't spared some good-natured ribbing from his teammates.
"They made fun of me, because I missed a chance in regulation and they were joking around that I wanted to play more," he said, laughing.
Another potential dream last week didn't turn out the way Hoppenot would like, but that's life in pro soccer.
It occurred during Saturday's 1-0 loss to visiting D.C. United when Hoppenot hit the post from close range.
Even though the Union didn't score, Hoppenot gave the team a major spark, constantly buzzing around the net, looking nothing like a supplemental draft pick.
"He is really annoying to play against," said Union forward-midfielder Freddy Adu. "Once in the game, every time you get the ball we are looking for him because he's fast and always running."
Imagine, the famous Freddy Adu, looking to pass to Antoine Hoppenot. We're guessing that wasn't a suggested scenario in preseason, or even a month ago.
"He's a spark plug," said interim team manager John Hackworth. "He's dangerous."
This is a story about perseverance.
Even though Hoppenot was a three-time first-team all-Ivy League selection at Princeton, he was starting at the absolute bottom when he joined the Union.
"I knew I would have to work hard just to make the team and work even harder to get to play," he said.
In this case, hard work paid off.
Hoppenot made the most of competing in reserve league games, which are sort of the MLS junior varsity. And he's enjoying himself now on the varsity.
"It's given me confidence," he said. "I have been able to play and contribute to the team."
In such a complex game, his job has been simplified.
"They tell me, 'Go out there and run,' and I go out there and keep running toward the goal," he said.
Don't be surprised if the running again occurs in the second half during Saturday's 7 p.m. matchup at PPL Park against Sporting Kansas City.
Hoppenot has been a natural energizer in his role off the bench. The Union (2-8-2) can use any offensive spark they can get, from Hoppenot or anybody else.
While it's a thrill to step onto the field, he's now past that point. Hoppenot is looking to do some damage in MLS.
He has seen his season turn around and he wouldn't mind the same happening for his team.
MLS All-Star Game coach named. The league announced that D.C. United coach Ben Olsen will lead the MLS All-Stars against UEFA Champions League winner Chelsea at PPL Park in Chester on July 25.
The Union's Hackworth will serve as an assistant coach, along with Olsen's D.C. United technical staff.
U.S. to play in Mexico. The United States will face rival Mexico on Aug. 15 in Mexico City, the first exhibition between the two on Mexican soil since 1984.
Contact Marc Narducci at 856-779-3225, firstname.lastname@example.org, or follow on Twitter @sjnard.
This article contains information from the Associated Press.