The source, an executive with another big-league club, said the Orioles appear to be the most aggressive suitor currently for Greinke, the 2009 American League Cy Young Award winner who is a free-agent at the end of the season.
The Orioles -- who remain in second place in the American League East despite demoting three-fifths of their rotation to Triple-A Norfolk last week -- are obviously seeking pitching.
And Orioles executive vice president Dan Duquette, who never talks trade specifics, has said the team will do what it takes to remain in contention in 2012 and that he "absolutely" has the financial support from ownership to take on salary this season if necessary.
In that context, Greinke, who is making $13.5 million in the last year of his deal, would likely be the best fit and biggest splash for the Orioles. The 28-year-old is 9-2 with a 3.08 ERA in 17 starts for the Brewers. He has fanned 106 batters and walked just 24 in 108 innings.
But it takes two teams to make a deal -- and the Orioles may not have what it takes to acquire Greinke if he is made available by the Brewers, who are 38-44 and eight games behind the surprising Pittsburgh Pirates in the National League Central.
The Brewers paid a heavy price in December 2010, when they sent four players to the Kansas City Royals -- including shortstop Alcides Escobar, outfielder Lorenzo Cain and top pitching prospect Jake Odorizzi -- for Greinke and infielder Yuniesky Betancourt.
And they would want a hefty bounty in return, even if Greinke, who has battled depression issues and injuries to be considered one of the better pitchers in baseball, is perceived as a two-month rental.
The Orioles arguably have two of the 10 best prospects in baseball in pitcher Dylan Bundy and shortstop Manny Machado, but it's highly unlikely the club would deal either. Duquette has not said they are untouchable, but he also says he wants to build through the system and those two are the only widely regarded prospects in the organization.
Others, such as L.J. Hoes, Jonathan Schoop, Parker Bridwell and Xavier Avery, are not universally considered sure-fire, major league regulars and, therefore, likely would not be a centerpiece in a deal for a top pitcher.
In fact, the popular belief is that the Orioles may have to settle for a second-tier available pitcher -- a Joe Saunders, Bartolo Colon type -- because other teams have deeper systems and can outbid them for the most coveted pitchers.
What could change the equation is if an opposing team believes it can get the most out of one the "cavalry" pitchers that are currently in Norfolk: Brian Matusz, Jake Arrieta or Zach Britton. The Orioles would be selling low on any of the trio -- they would likely have to include one of those as part of a prospects package for Greinke, and that still may not be enough in comparison to other teams' offers.
The Orioles do not want to give up young pitching if they can help it, but it would be the only way they could keep Machado and Bundy and still obtain a potential difference-maker. And, again, that's only if a trading partner sees the potential -- and not the recent, big-league results -- of a Matusz, Arrieta or Britton.
In that scenario, what's intriguing about the Brewers is that their pitching coach is Rick Kranitz, who held the same spot for the Orioles when Matusz, Arrieta and Britton were rising in prominence. Kranitz, for instance, saw Matusz at his best in the final two months of 2010.
If the Orioles were able to land Greinke via trade but not sign him to a long-term deal, they would not receive compensation picks in the draft. The new collective bargaining agreement stipulates that teams are only given picks if they lose a player who'd been on their roster the entire season.