Zack Greinke trade rumors have kicked up a few notches over the last 12 hours after reports surfaced that prized free agent Cliff Lee signed with the Philadelphia Phillies.

Lee’s decision to sign with the Phillies over a larger offer from the New York Yankees and extreme interest from the Texas Rangers all but shocked the baseball world.

Lee joins Roy Halladay, Roy Oswalt and Cole Hamels in what will be perhaps the top starting rotation in all of baseball.

Throughout the highly anticipated free agency process, Greinke has served as sort of a backup option to teams in the event they did not land Lee.

Given the fact that both the Yankees and Rangers, along with the Los Angeles Angels of Anaheim, have lost out on Lee and other prized free agents, expect the interest in a trade for Greinke to only increase.

Prior to news of Lee’s deal with the Phillies, it was reported that the Yankees would be reluctant to go after the Kansas City Royals right-hander if they missed out on Lee. New York’s contingency plan in the event that it lost out on Lee has always been focused on beefing up the bullpen.

Of course, these reports surfaced prior to news of Lee signing and when the Yankees, who had reportedly offered Lee a seven-year, $148 million deal, were bound to land the free agent. One can only wonder if New York’s Plan B changes this morning with the confirmation of Lee’s five-year, $120 million deal with Philadelphia.

Late Monday night, ESPN.com’s Jerry Crasnick reported that the Kansas City Royals were “actively gauging” the trade market for Greinke. The Royals are reportedly looking for up-the-middle position players close to being ready for action in the big leagues. The report noted that the Yankees and Brewers were not among the best potential matches for a trade.

Other potential landing places for Greinke predicted in reports over the last few days include the Washington Nationals, Los Angeles Dodgers and Los Angeles Angels of Anaheim.

With Lee off the table, Greinke is perhaps the top pitcher available for teams interested. The Royals know well that when Greinke becomes a free agent at the end of the 2012 season, they’re unlikely to have the resources to retain him.

All of that said, I don’t think this will come down to the bigger market teams like the Yankees swooping in and picking the right-hander up. The Royals value prospects highly, and it’s going to take the right package for Kansas City general manager Dayton Moore to pull the trigger.

The deal Lee signed is bound to leave the MLB Players Union scratching its head. Lee left money and years on the table by signing with Philadelphia. Both New York and Texas had reportedly offered him more than the five-year, $120 million deal he inked with the Phillies.

When it comes time for his next payday—regardless of which team it will be with—Greinke’s contract will surely be impacted by the bargain deal Lee signed.

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