But what if they hit an impasse with Zack or the Brewers fall out of contention by July? I know they have the talent and roster to win the NL Central again, and this is just a "what if" slideshow.
I will break down my ideal trade partners for the Brewers if talks break down or the Brewers struggle to contend.
While I hope they sign Greinke to a long-term, the prospects of seeing the return for Greinke via trade is intriguing.
Zack Greinke has been phenomenal since being acquired two winters ago.
The Brewers gave up a lot to get Greinke, with young, talented players like shortstop Alcides Escobar, centerfielder Lorenzo Cain, and relief pitchers Jake Odorizzi and Jeremy Jeffress going to Kansas City.
But Greinke is certainly worth it. He has yet to lose at Miller Park and has a record of 12-0, and Greinke continued his Miller Park mastery against the Cardinals April 7, by tossing a shutout.
As a Brewer, Greinke is 17-7 with a 4.00 ERA, but that's due to the 6 ER he gave up in Chicago this season. He has pitched better than the numbers indicate.
I think a deal of five years and $100 million signs him up.
But if not, here are some of my scenarios.
DODGERS ACQUIRE: SP Zack Greinke.
The Dodgers already have a young shortstop in Dee Gordon and seem to be set with him as the shortstop of the future.
In the deal, the Dodgers acquire Greinke and add him to a rotation that consists of Clayton Kershaw and Chad Billingsley. This deal gives the Dodgers a three-headed monster rotation.
BREWERS ACQUIRE: SS Ivan DeJesus JR., LHP Chris Reed and 1B Angelo Songco.
The Brewers ship Greinke to the Dodgers for three major prospects from the Dodgers. Ivan DeJesus JR is blocked in LA and would become the shortstop of the future in Milwaukee.
Chris Reed is a big, powerful left-hander who has a chance to be a mainstay in the Brewers rotation in two or three years. A 2014 rotation of Yovani Gallardo, Wily Peralta, Taylor Jungmann, Jed Bradley and Chris Reed would be a good one.
And finally, the Brewers acquire a first baseman in case Mat Gamel doesn't work out. Songco could add some weight and become more of a power hitter.
RED SOX ACQUIRE: SP Zack Greinke.
The Red Sox have the payroll space to accommodate Greinke's demands, and they pull the trigger. Greinke may not do well in a big city, but he is worth the risk for the Sox.
Added to a rotation with stars like Jon Lester and Clay Buchholz, Greinke would give the Sox another reason they'd run rampant in the AL East.
BREWERS ACQUIRE: SS Jose Iglesias, 3B Garin Cecchini, OF Brandon Jacobs and 1B Lars Anderson.
The Brewers acquire four pieces for Greinke, which all could be cornerstones of the future in Milwaukee.
They acquire Iglesias who may only be in Boston until the Aruba-native Xavier Bogaerts arrives. Iglesias would fit nicely in Milwaukee's everyday lineup. They also acquire third baseman Garin Cecchini who is blocked by Youkilis and young power bat Will Middlebrooks.
He could learn under Aramis Ramirez until his deal runs out or Cecchini proves to be better. The last two prospects are solid throw-ins, and they are capable of being contributors.
Jacobs is a good outfielder and hits for average and power. Lars Anderson has been the forgotten man in Boston now that Adrian Gonzalez has locked it down. He could compete with Gamel or take over next year.
RANGERS ACQUIRE: SP Zack Greinke.
The Rangers add another rotation piece to help replace the departed C.J. Wilson.
The Rangers committed a lot of money to Japanese/Iranian sensation Yu Darvish, but I do not think that will hold them back from acquiring Greinke. Greinke teams up with Darvish and Colby Lewis to form the elite top end of their rotation.
BREWERS ACQUIRE: SS Elvis Andrus, CF Leonys Martin, RHP Roman Mendez.
The Rangers have a superstar-in-waiting by the name of Jurickson Profar, which could lead to Andrus becoming expendable.
The Brewers would sprint to the phone to finalize the deal, if Andrus becomes part of the deal. The Brewers get their shortstop of the future along with a toolsy center fielder with starter qualities.
And to round out the deal, the Brewers get a young power arm in Roman Mendez. He can become a solid piece to the rotation or the bullpen with his 96 mph fastball.