If playing three games in eight days earlier this month seemed tough, the Union are facing a more-difficult stretch.

Saturday's scoreless tie at the New York Red Bulls began a string of five games in 14 days. The next match comes up Wednesday, when the Chicago Fire visit Talen Energy Stadium (7:30 p.m., PHL17).

After that, the Union head to high-flying Atlanta United on Saturday (7:30 p.m., PHL17), then return to Chester for a U.S. Open Cup game against the Richmond Kickers on June 5. Toronto FC will visit on June 8.

"The most important game is Chicago — that's our focus right now," coach Jim Curtin said. "It's at home and a conference opponent, so you have to focus on what's the best lineup to win that game."

It's also a game that the Union stand a much better chance of winning than they do Saturday. Atlanta (8-3-1, 25 points) has the best record in the MLS, while the Fire (4-6-2, 14 points) sit below the Union (4-5-3, 15 points) in the standings.

Curtin said he expects to keep "the core" midfield triangle of Borek Dockal, Alejandro Bedoya, and Haris Medunjanin together as much as he can and that changes are more likely to "the front three."

That likely means a return to action for Cory Burke, who has impressed in his two appearances this season. It also might affect David Accam, who's been a substitute for three straight games. Wednesday's game will be his first shot to face the Fire since they traded him to the Union in January.

"There will be a little something extra in the game for him," Curtin said. "He'll play a role in the game one way or the other. … I know what role that is, but I'm not going to reveal that for a while."

Pulisic out, Steffen in as U.S. men’s national team changes roster

As was widely predicted, Christian Pulisic has been let go from the U.S. national team's roster as the squad heads to Europe. The Hershey native was one of seven players who were released. Trenton native Matthew Olosunde, who made his senior national team debut in Monday's win over Bolivia, was another.

Also dismissed were goalkeepers Alex Bono and Ethan Horvath, defender Walker Zimmerman, and midfielders Alejandro Guido and Lynden Gooch.

Coatesville-born goalkeeper Zack Steffen was one of 10 players summoned to join the squad. Midfielder Tyler Adams was another notable addition; he's likely to partner with Weston McKennie in central midfield. There's some veteran firepower in the group too, in right back DeAndre Yedlin and striker Bobby Wood.

The other additions were goalkeeper William Yarbrough, defenders Shaq Moore and Tim Parker, and midfielders Tyler Adams, Luca de la Torre, Kenny Saief and Wil Trapp.

The U.S. will play the Republic of Ireland in Dublin on June 2 (3 p.m., ESPN2 and UniMás), and World Cup-bound France in Lyon on June 9 (3 p.m., ESPN and UniMás).

U.S. roster for European tour

Goalkeepers (3): Bill Hamid (Midtjylland, Denmark), Zack Steffen (Columbus Crew), William Yarbrough (Club León, Mexico)

Defenders (9): Cameron Carter-Vickers (Tottenham Hotspur, England), Eric Lichaj (Nottingham Forest, England), Matt Miazga (Chelsea, England), Shaq Moore (Levante, Spain), Erik Palmer-Brown (Manchester City, England), Tim Parker (New York Red Bulls), Antonee Robinson (Everton, England), Jorge Villafaña (Santos Laguna, Mexico), DeAndre Yedlin (Newcastle United, England)

Midfielders (10): Tyler Adams (New York Red Bulls), Joe Corona (Club América, Mexico), Luca de la Torre (Fulham, England) Julian Green (VfB Stuttgart, Germany), Weston McKennie (Schalke 04, Germany), Keaton Parks (Benfica, Portugal), Rubio Rubin (Club Tijuana, Mexico), Kenny Saief (Anderlecht, Belgium), Wil Trapp (Columbus Crew), Tim Weah (Paris Saint-Germain, France)

Forwards (3): Andrija Novakovich (Reading, England), Josh Sargent (Werder Bremen, Germany), Bobby Wood (Hamburg, Germany)

Union at Chicago Fire

Wednesday, 7:30 p.m. at Talen Energy Stadium

TV: PHL17

Union's record: 4-5-3, 15 points (7th in the East); 3-1-2 at home
Chicago's record: 4-6-2, 14 points (8th in the East); 2-2-1 on the road

All-time series: Union 7 wins, Fire 8 wins, 5
At Talen Energy Stadium: Union 5 wins, Fire 2 wins, 2 ties

Chicago players to watch

D Bastian Schweinsteiger: The longtime midfielder has played as a defensive sweeper this year, and he's been pretty good at it.

F Nemanja Nikolic: Last year's Golden Boot winner is at it again, with six goals in 12 games.

F Alan Gordon: The veteran striker has an incredible knack for scoring goals late in games, including 22 goals off the bench in his 14-year career. He struck again Saturday with an 81st minute game-winner at Orlando.