The Union are one win away from earning the first championship in the five-year history of the team. Interim manager Jim Curtin showed how much Tuesday night's U.S. Open Cup final meant to the Union when he held several regulars from the starting lineup Saturday in a 2-2 Major League Soccer draw with the New York Red Bulls.

The outcome left the Union tied for the fifth and final MLS Eastern Conference playoff spot with six games left.

The full starting lineup is expected to be ready Tuesday when the Union host the Seattle Sounders in the title game at PPL Park.

The Open Cup is open to all affiliated amateur and professional teams in the United States. Seattle won three straight Open Cups from 2009 to 2011 and was in the 2012 final, but the Union might be the hungrier team in this matchup.

"It's a huge honor to try to raise the club's first trophy," said defender Sheanon Williams, one of the regulars who was given Saturday off. "I have been here since the end of the first year and know what it means to the city, the fans, to this team, to this organization, and we are gung ho on trying to win this."

Three of the regulars who were not in Saturday's starting lineup - Sebastien Le Toux, Cristian Maidana, and Vincent Nogueira - were inserted at various points in the second half, and all made major contributions.

Le Toux began his U.S. professional career with Seattle and won an Open Cup with the Sounders in 2009. Since 1995, he has scored the most Open Cup goals, with 14.

"I have been to the final one time and we won it, and it is a good memory," Le Toux said. "It's very important to me to win a second trophy."

Curtin has won twice as a player with the Chicago Fire in 2003 and 2006. A native of Oreland who attended Bishop McDevitt High and Villanova, Curtin has deep Philadelphia sports roots.

"Being from here, I feel a little bit more the weight not to let the city down," said Curtin, whose team's MLS record is 9-9-10. "We want to win, and that is kind of the idea. I preached trying to win from the start here."

Both Curtin and Seattle coach Sigi Schmid said Monday that their teams are as healthy as they have been.

Seattle, which has the best record in Major League Soccer at 17-7-3, is coming off Friday's hard-fought, 3-2 win over visiting Real Salt Lake. The Sounders played their available regulars in that game.

When asked if he would be playing all his starters Tuesday, Schmid was not ready to commit.

"We have three to four things up in the air and will decide [Tuesday morning] how to proceed," Schmid said.

A star such as Clint Dempsey has yet to play in any Open Cup games this season for Seattle. Schmid will keep everyone guessing on his lineup.

There is no guessing with the Union. Their best players will play.

As of late Monday afternoon, about 13,000 tickets had been sold, according to a team official. PPL Park's capacity is 18,500.

Seattle Sounders at Union

Tuesday at 7:30 p.m., PPL Park

TV: The Comcast Network

MLS Records: Seattle, 17-7-3; Union 9-9-10.

Coaches: Seattle, Sigi Schmid; Union, Jim Curtin (interim manager).

Most recent meeting: May 3, Seattle won, 2-1, at home in an MLS game.

Open Cup semifinals: Seattle beat the Chicago Fire, 6-0, on Aug. 13; The Union beat FC Dallas, 4-3, in penalty kicks, after a 1-1 draw, Aug. 12.

Other Open Cup wins: Seattle - PSA Elite, 5-0; San Jose Earthquakes, 1-1, 4-1 in penalty kicks; Portland Timbers, 3-1 in OT; Union - Harrisburg Islanders, 3-1, in OT; New York Cosmos, 2-1, in OT; New England Revolution, 2-0.

Leading scorers (MLS games): Seattle - Obafemi Martins, 13 goals, 9 assists; Clint Dempsey, 11 goals, 7 assists; Chad Barrett, 7 goals, 1 assist. Union - Sebastien Le Toux, 12 goals, 6 assists; Conor Casey, 8 goals, 2 assists; Andrew Wenger, 5 goals, 4 assists.

Most recent game: Seattle beat Real Salt Lake, 3-2, on Friday in MLS. The Union played the visiting New York Red Bulls to a 2-2 draw Saturday, also in MLS play.

Outlook: The Sounders won three consecutive Open Cups from 2009 to 2011 and were finalists in 2012, and five players are on the team from the 2011 championship squad. . . . Seattle keeper Stefan Frei has eight shutouts and a 1.37 goals-against average in 27 MLS games. . . . Curtin wouldn't say who would be his keeper, but all signs point to two-time Algerian World Cup goalie Rais Mbolhi, who has only appeared in one game for the Union. Le Toux has the most Open Cup goals in the modern area (1995 to present) with 14, while Seattle's Cooper is second with 13.

- Marc Narducci