Every general manager constantly wrestles with these kinds of questions, especially if he has a team with a legitimate World Series aspirations and a deep farm system.
The Cards check off both boxes. They're one of the few clubs with enough coveted prospects -- outfielder Stephen Piscotty, left-hander Marco Gonzales, etc.-- to get Phillies senior vice president and general manager Ruben Amaro Jr. to pull the trigger on this trade.
This is why the Cardinals are among the most respected franchises in the game. They do things right, top to bottom. They've managed their payroll smartly and built a tremendous farm system.
At some point, there's a time to take the plunge -- that is, to spend big for a free agent or to trade some of those prospects to make an impact addition to the Major League roster.
Amid reports that Mozeliak is considering making a play for a top-of-the-rotation starter to his rotation, he appears to have three choices:
1. Max Scherzer
3. David Price
St. Louis is already the favorite to win the National League Central for a third straight season. In Adam Wainwright, Lance Lynn and John Lackey, it has three starters who can line up against most of the other Nos. 1-3 in the game.
After that, there's uncertainty. Michael Wacha and Jaime Garcia are attempting to bounce back from injuries. Gonzales and Carlos Martinez have made 13 big league starts between them.
These seven starters could comprise the best rotation in all of baseball. There's an amazing amount of talent, and in those young guys, huge upsides. Plenty of teams would love to go to Spring Training with that kind of talent and depth.
On the other hand, the Cardinals have a different bottom line. Anything less than an NL pennant would be a bitter disappointment. At a time when baseball's landscape has shifted amid competitive balance, the Nationals, Dodgers and Giants all have the same expectations.
Look at the NL Central: The Pirates are really good. The Cubs are about to be. The Reds are good, too, if they can get their big guys back on the field.
So do the Cards play an already strong hand, or do they shove their chips onto the table?
As for Price, Scherzer and Hamels, they fall into two categories. Scherzer would only cost the Cardinals money -- a lot of it. He's a Missouri native and might jump at the chance to return.
But the Cards have a history of avoiding big-ticket deals for free agents. They do have the payroll flexibility, but Scherzer appears not to be the first guy on Mozeliak's radar screen.
And so there are Price and Hamels. Both are left-handers, which is significant for a rotation with three right-handers at the top.
But Price is a year from free agency. And while the Tigers appear willing to listen to offers, the contractual component is huge.
Hamels, 31, has none of those issues. He'll earn $23.5 million for each of the next four seasons, which is less than Clayton Kershaw and Jon Lester will be paid by the Dodgers and Cubs, respectively.
In the past three seasons, Hamels has ranked eighth in the Majors in ERA (3.05, tied with Price and Wainwright), eighth in innings and eighth in strikeouts. He has 73 quality starts in that time, behind only Kershaw (76). Hamels compiled these numbers while playing for teams that weren't great. In 13 postseason starts, he has a 3.09 ERA.
Impressive, huh? If St. Louis opened next season with a rotation of Wainwright, Hamels, Lynn and Lackey, it would be as positioned to win the World Series as a team could be.
Again, there are no guarantees. But coming off a disappointing loss to the Giants in the NL Championship Series, and with the landscape so blurry, the Cardinals surely are tempted to do something bold. Hamels would qualify.