Zack Greinke stared down the Nationals on the biggest stage of all: Game 7 of the World Series. But do you remember that once upon a time, he almost pitched for them?

In December 2010 -- when Greinke was still with his original MLB team, the Royals, the Nationals had never been to a postseason and Washington's October heartbreak and redemption were still to come -- the Nats nearly traded for him.

Greinke, then 27, had just won the American League Cy Young Award in 2009. He wanted a trade out of Kansas City. The Nats were trying to build themselves into a contender after years of last-place finishes in the National League East. They wanted Greinke, they were far into negotiations with the Royals to get him and they were prepared to give Greinke a $100 million contract extension if he came to Washington.

But the trade fell through when Greinke invoked his no-trade protection. Greinke wanted to go to a team that was in "win now" position after experiencing seven straight losing seasons with the Royals. Instead, after switching agents, Greinke worked out a trade to the Brewers that did not include a contract extension.

"It wouldn’t have gotten as far as it did [with the Nationals] if it wasn’t appealing," Greinke told the Washington Post at the time. "The one thing I couldn’t get over was the fact that, here I was trying to get out of Kansas City because the team wasn’t good. Not saying [the Nats] don’t have a chance, but I was trying to get to a team that was looking really good at the moment. And I believe [the Nationals] will be good eventually."

Nine years later, the Nats are so good that they've taken Greinke's Astros to a winner-take-all World Series finale.

Since 2010, Greinke has pitched in six postseasons -- including '11, his first season in Milwaukee -- for four teams: the Brewers, Dodgers, D-backs and Astros. But the 36-year-old is still looking for his first World Series ring. The Nationals, meanwhile, have been to five postseasons, but they're looking for their first title, too, after four straight NL Division Series exits before this year.

We'll never know what would have happened if Greinke ended up in a Nats uniform. But one side is about to win a championship, and we're about to find out which.