United (8-4-3, 27 points) leads the 10-team Eastern Conference. The Union (2-7-2, 8 points) are in ninth place.
At least Hackworth has a few factors in his favor.
For one, there will be no shortage of players out to impress the new boss. In addition, the Union know that they can beat United, because they did exactly that on June 5, in a 2-1 victory in the U.S. Open Cup.
That win didn't help the Union in the MLS standings, but certainly will provide confidence that they can get the Hackworth era off to a good start.
After serving as an assistant, Hackworth now has the final hammer when it comes to playing time, which should get everybody's undivided attention.
He used an old line when asked about his feeling approaching the game.
"This isn't my first rodeo," he said.
No, but it should be some ride.
Hackworth was often the team's good cop, and Nowak the bad cop. The new coach seems a lot calmer than his old boss.
Then again, an exploding volcano would appear calmer than Nowak.
As for Hackworth, his other rodeos included four seasons as head coach at the University of South Florida, where he went 47-32-2 and earned NCAA tournament appearances in 1998 and 2001.
He was also a head coach for six years with the U.S. under-17 residency program in Bradenton, Fla.
And he actually had to guide the Union at times in Nowak's absence. So he knows the drill.
Because Hackworth has been with the Union since their inception, he has a deep knowledge of every player on the roster, along with virtually every opponent.
Nowak often would have Hackworth meet with the press, and he was always poised and informative.
That doesn't automatically translate to winning MLS games, but Hackworth appears ready for the challenge.
The feeling was that Hackworth would eventually be a head coach, and possibly of the Union. This appointment probably came a little sooner than expected.
Yet Hackworth won't get a long honeymoon.
Make no mistake. This season will be judged to be successful only if the Union can get back into the playoff race.
The top five teams in the Eastern and Western Conferences will make the playoffs, and even though the Union are ninth, they are only about one three-game winning streak from contention. With 23 games remaining, there is still plenty of time.
"Everybody at the top knows that if you win three in a row you can get back in the picture - and if you lose three in a row you're back out of the picture," said Hackworth, who has also served as an assistant with the U.S. national team and at his alma mater, Wake Forest. "That is a positive, and it gives everybody this time of year a lot of hope."
Now the Union are pinning their hopes on Hackworth, who enters this new challenge with a quiet confidence and an expectation of guiding the Union for years to come.
Contact Marc Narducci at 856-779-3225, firstname.lastname@example.org,
or follow on Twitter @sjnard.