Jim Curtin hopes the Union have woken up after their ugly loss in Charlotte

The Union have been atop the Eastern Conference for so long now that they haven’t had many occasions lately to be genuinely upset with themselves. But last Saturday’s 4-0 loss at Charlotte was thorough enough to merit being in a sour mood this week.

While the loss was bad, the mood might not be a bad one to have heading into Sunday’s regular-season finale against Toronto FC. Second-place CF Montréal has lost just one of its last 14 games dating back to mid-July and has risen to within two points of the Union in the standings.

Combine that with the Charlotte game’s costing the Union a shot at the Supporters’ Shield, and all the ingredients are there for a resharpening of focus ahead of Sunday’s game (2:55 p.m., PHL17; TV coverage starts at 2 p.m., and there will be postgame coverage until 5:30.).

“It’s good to get a wake-up call like that and maybe take one on the chin and get soundly beaten as you go into elimination games,” Curtin said. “If we start with not being us, you can get punished quickly, and in the playoffs, it’s one bad game and you’re done.”

» READ MORE: JP Dellacamera says farewell after 13 years as the Union's lead TV play-by-play broadcaster

The Union (18-5-10, 64 points) will be without Kai Wagner on Sunday, as he is suspended because of a red card he got in Charlotte. Matt Real will stand in for him.

But Olivier Mbaizo should return at right back after missing the Charlotte game. He took a round trip to South Korea to be with Cameroon’s national team, didn’t play in either of the Indomitable Lions’ warmup contests, picked up a minor injury on top of that, and got back to Philadelphia only two days before the Charlotte game. So Curtin let Mbaizo rest.

“We just didn’t think it made sense,” Curtin said. “Olivier will certainly play a very big role in the game here.”

The big question is what happens with Alejandro Bedoya, who missed the Union’s last two games — Charlotte and the scoreless tie at Atlanta on Sept. 18. Bedoya practiced to the side Thursday and Friday and was in full training Saturday but ran with the backups.

Curtin said his captain’s “body responding is as good as it has recent in recent weeks — the hope is that he’s part of the group against Toronto.”

There’s also a guessing game to play about whom Toronto will line up with. The Reds have big stars in Italians Lorenzo Insigne and Federico Bernardeschi, and American veteran Michael Bradley. But they are next-to-last in the East (9-17-7, 34 points) and have long been out of the playoff race.

» READ MORE: The Union lost a game in Charlotte, the Supporters’ Shield to LAFC, and Kai Wagner to a suspension

Will Toronto manager Bob Bradley, who coached Curtin back in the day in Chicago, run out his full squad or give his young prospects the spotlight? (And what will Toronto’s archrival, Montreal, think of it, by the way?)

“What we can control is how we play in our building,” Curtin said, “and I think our guys, off the tough Charlotte loss, will have a good response.”

He left it at that.

The last day of the MLS regular season, nicknamed Decision Day, is a perennial highlight of the calendar. Every Eastern Conference team kicks off at the same time (2:55 p.m. this year), and every Western Conference team kicks off at the same time (5:18 p.m.).

For the Eastern Conference games, FS1 and Fox Deportes will highlight Orlando City vs. the Columbus Crew and have whip-around coverage of the other action. For the Western Conference games, ESPN2 will highlight Real Salt Lake vs. the Portland Timbers and have its own whip-around coverage.

The full broadcasts of all games not on TV will be live on ESPN+.

When all the day’s action is done, we’ll wait to learn the MLS playoffs schedule. It hasn’t been announced yet, and traditionally isn’t until after the regular season is over.

» READ MORE: The Union will move their academy from Wayne to Chester and build a new soccer complex next to Subaru Park

Here’s which teams are alive in each conference, and what the key games are to follow. A reminder that the first tiebreaker is total wins, and the second is goal difference.

The top seven teams in each conference qualify, and the first-place finisher gets a first-round bye. In the East, five teams have clinched berths, and three teams are alive for the last two spots.

Key games: Union vs. Toronto FC, Montréal vs. Miami, Atlanta vs. New York City, New York Red Bulls vs. Charlotte, D.C. United vs. Cincinnati, Orlando vs. Columbus

Five teams have clinched berths, and four teams are alive for the last two spots. First-place Los Angeles FC and second-place Austin FC have locked up those places.

Key games: LAFC vs. Nashville, Dallas vs. Kansas City, Houston vs. L.A. Galaxy, Minnesota vs. Vancouver, Real Salt Lake vs. Portland