There were quite a few surprised looks around Talen Energy Stadium when Sergio Santos jogged over to the Union’s bench to enter the game as a second-half substitute Saturday night.

It made sense in a way, since Santos has the ability to play on the left wing. But he hadn’t seen the field for the Union since July 14, a stretch of six games, and Andrew Wooten -- a better striker, and certainly higher up the depth chart -- was also available.

By the end of the game, though, the doubts were silenced. Santos delivered an inch-perfect assist on the game-winning goal, then scored to seal the 3-1 victory over Atlanta United.

The win, combined with Orlando City’s loss at San Jose late Saturday night, clinched a playoff berth for the Union.

“You can see how explosive he is, how fast he is, and he is just a guy that defenders don’t like to play against, especially when he comes in with fresh legs,” Union manager Jim Curtin said afterward. “Really happy for him, because it is frustrating when you’re injured and you’re battling little things. You’re in for a month, then you’re out for two weeks, and that’s kind of how his season has been."

Santos was a Targeted Allocation Money signing before the year started, bringing expectations that he willingly embraced. The Brazilian hasn’t fully lived up to them, though. Saturday’s goal was just his fourth of the season, and his first since May 30. The assist was his first since June 2.

It certainly hasn’t helped that Santos has missed two major stretches of playing time this year: seven games in March and April due to a knee injury, and the last six due to an ankle injury. Nonetheless, his lack of goals raised questions, as did his making just six starts in 15 appearances for the Union so far.

The landscape looks better now.

“When I signed for this club, I knew that I came here to work, and that’s what I want to do,” he said through an interpreter.

Santos’ efforts drew a strong endorsement from Union midfielder Ilsinho, who has worked to help his fellow Brazilian navigate his first year in MLS.

“This kid has a lot of power [and] speed,” Ilsinho said. “If he puts it in a smart way -- we try to help him a lot -- if he puts that power and that speed in the right way, like he did tonight, he’s maybe one of the most dangerous players in the league.”

That level of talk still feels like hype as of now. But at least for one night, the talk was backed up with substance.