Kreis soon must decide whether to stay with RSL or accept a job offer from the New York expansion franchise.
In the buildup to this game, Kreis said the outcome would not affect his choice as RSL pursued a second championship in five seasons.
He offered no clues afterward, while publicly thanking his team for give him "the funnest season I've ever been a part of."
RSL's players don't know what to expect, but they're prepared for a move.
"I would hope he'd stay, for sure," veteran defender Nat Borchers said. "But if he does end up leaving, I'll respect his decision. He's an ambitious guy, and you've got to be happy for him when he wants to make a change and further his career."
Kreis potentially could position himself to coach the U.S. National Team or a prominent European club by succeeding with another franchise.
If he moves on after seven years as RSL's coach, Kreis will have a strong legacy. He went from being the face of the franchise as a player to a suddenly promoted, unproven coach early in the 2007 season.
Beginning in '08, he's made six straight playoff appearances, with two MLS Cup finals and two other conference finals berths.
RSL also came close in the CONCACAF Champions League and the U.S. Open Cup. Kreis hopes the franchise is known for repeatedly putting itself in position to win trophies, rather than failing to deliver them.
Kreis tried to give his players a positive message in the locker room, even while knowing the loss was hurting them. His lasting image of the season would not be how it ended, he said in a news conference, but the way the players responded to one another. Watching a highlight video shown during a team dinner in Kansas City, he was struck by the reaction shots of the players, thrilled about their teammates' success.