In addition to the No. 1 MLS comeback story, the Union are another thing: Completely unpredictable.

Indiana Vassilev’s body language coming off the field could have served as a metaphor for the Union’s entire performance.

As he exited the pitch at Nashville SC’s Geodis Park, Vassilev needed a second to collect his breath and give his legs a heat check after 86 minutes of scratching and clawing against a club that has found a way to rattle off 21 wins and just three losses (8 draws) en route to already locking up a top seed in the upcoming MLS Cup Eastern Conference playoffs. Nashville SC earned the Supporters’ Shield, given to the team with the best points total (now 71 points) in the league.

It was always going to be an uphill climb, and it was. Nashville held the edge in possession 65-35, and rattled off more shots (eight to the Union’s six). They did so for a good chunk of the match without their two biggest goal-scoring threats, Hany Mukhtar and Sam Surridge, the latter of whom leads Nashville with 18 goals this season.

Even when Nashville coach and former Union assistant B.J. Callaghan put in both players in the 58th minute, the Union were able to defend against the flurry of chances they helped create in their short time on the pitch.

Bottom line: This Union team is completely unpredictable.

This was a game they weren’t supposed to pull any points from, at least according to national soccer pundits and Vegas oddsmakers. The team was without three players who accounted for 38 of their 59 combined goals in MLS action this season, including their leading goal scorer in Milan Iloski (19 goals), who was out Wednesday with a hamstring injury.

» READ MORE: The Union clinch a playoff berth and hold MLS-leading Nashville to a scoreless tie

They also were without the electrifying playmaking ability of their youngest player in superstar Cavan Sullivan, who is still trying to return from an ankle injury sustained in a draw two weeks ago against Charlotte FC. Instead, head coach Ryan Richter trotted out a ragtag collective, particularly on attack, electing to give youngster Malik Jakupović his first start against the best team in MLS, statistically speaking.

Go get ‘em, kid.

He played the big body of Ezekiel Alladoh, who received just his seventh MLS start, but was unable to do much with it in his 69-plus minutes on the pitch.

“I’m proud of the effort, really from everybody, [especially] for the guys who have been called upon to get more minutes than they have been getting in the past few weeks,” Richter said in his postgame conference. “[They] really stepped up and did the job that the team asked [for], so I’m just proud of the guys and happy overall with the effort that was put in tonight.”

» READ MORE: Interim tag aside, Ryan Richter has as good a chance to win MLS’s Coach of the Year as anyone | Opinion

Defensively, the backline was a shuffle with Frankie Westfield given the night off, Nathan Harriel was arguably the team’s man of the match in the back, flying over Nashville attackers to head attempts on the Union’s goal back up field, and repeatedly denying would-be strikes at goalkeeper Andre Blake.

“Tonight was a team performance that led to that,” said Richter, referencing the fact that from the outset, the Union were trying collectively to do their part to not give up what he described as “preventable goals.”

Added Richter: “From the front line all the way to [goalkeeper] Andre [Blake], it’s not just a great performance from the defenders, but it was the work against the ball and what the guys [collectively] were committed to.”

The efforts of players like Harriel and others did not go unnoticed on a night in which the Union not only had an opportunity to have another statement game, much like it did last month in a win against Orlando City, but for an opportunity to secure a trip to the upcoming MLS playoffs.

» READ MORE: With an unbeaten streak behind them, here’s a look at the Union’s climb to make the MLS playoffs

At halftime, they knew the results of one of three possible scenarios that had to go their way, in that if they could hold onto a draw, they’d book their trip to the postseason courtesy of a 3-2 New England defeat of Red Bull New York earlier that night. It’s not lost that the player who scored the goal to give the Union a leg up, was former playmaker, and still the team’s all-time leading goalscorer in Daniel Gazdag.

Wonder if the thank you card is already in the mail. Assuming not, considering just three days prior, Gazdag frustrated his former team and fans inside Subaru Park for what was perceived as embellishing fouls to earn calls in the Revolution’s favor.

They say that soccer is 80 percent athletics, and 20 percent theatrics. If that’s true then Gazdag was just playing the part on Saturday. On Wednesday night, he played the role of motivator from 1,100 miles away in Foxborough, Mass., for a Union team that if not for some serious changes in late May would not be locked into a postseason spot or even anywhere near it.

But it speaks to the undeniable work rate they’ve exuded over the last three months, rattling off a franchise-record 15-game unbeaten streak with 12 wins nestled within. On Wednesday, it was topped off with a draw that took a Herculean effort from the Union that saw them keep a league giant at bay for 90-plus minutes inside their own ballpark.

Not an easy task. Just ask Vassilev’s knees.

While the statuses of Cavan Sullivan and Milan Iloski are still unknown, Richter did divulge that he felt strongly that midfielder Jesus Bueno could be available for action against FC Cincinnati. Bueno has missed three matches due to a hamstring injury. … a few numbers that stand out from the Union’s draw indicating just how much they were outmatched statistically. In addition to Nashville holding a dominant edge in possession, they also conceded fewer fouls (eight to the Union’s 15), and dominated the passing lanes (499-274). But the one stat that arguably burned their chances and aided the Union’s? Nashville attackers were called offsides six times.

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