And he's far from alone.
Look at the Mariners, who plucked ace lefty Erik Bedard out of Baltimore this winter. Check out the Diamondbacks, who snagged Dan Haren in a deal with the A's. One pitcher, these clubs have found, can radiate an immeasurable level of confidence. One pitcher can give his new fans a whole lot more hope than they may have once had.
Or, as Braves catcher Brian McCann put it after the National League East-rival Mets landed Santana in January, "Adding arguably the best pitcher in the game is going to make you better."
Better, sure. But the best? That much remains to be seen. Too many obstacles remain standing between April and October -- obstacles that can redefine rotations and reshape races. Calling any one rotation better than the rest might be a bit premature in March.
"You try to get your team ready and build depth, because you're going to need it," Red Sox manager Terry Francona said. "And if you think you won't need it, you're crazy."
Francona should know. Earlier this year, news hit that he would be without one of his own horses, Curt Schilling, for the bulk of the summer. Just like that, the Sox rotation fell from perhaps the best in the Majors to among the most uncertain. Though the Sox won the 2007 World Series in large part thanks to pitching, they're now relying on at least one -- and possibly two -- of the league's youngest starters to help defend their title. How quickly things change.
There are others in similar situations. The Dodgers might have cracked a list of baseball's top five rotations if not for Jason Schmidt's surgically repaired shoulder needing more time to recover. The Tigers might have made the cut if not for questions surrounding their depth. Even the Blue Jays and Yankees could have earned a mention if not for their heavy reliance on youth.
The truth is, so many rotations remain either a breakout away from becoming elite or an injury away from falling further into the pack. Yet a select few -- including the five listed below -- might just have the makeup and depth to carry their respective teams deep into October.
No. 5: Cleveland Indians
Of all the teams that can boast two legitimate aces -- see the Padres, Mariners and Diamondbacks -- the Indians just might have the best. Their top two starters, C.C. Sabathia and Fausto Carmona, proved how formidable they could be in boosting their team to within one game of the World Series last October, and there's no reason to believe they can't replicate that success in 2008. Even if the Indians receive virtually no support from veteran starters Jake Westbrook and Paul Byrd -- and certainly, that won't be the case -- they don't need to worry. Sabathia and Carmona are insurance enough.
No. 4: Los Angeles Angels
Kelvim Escobar will miss the beginning of the season, and John Lackey -- among the top pitchers in the game -- might as well. But all that's done is reveal exactly what makes this rotation so good. The Angels boast unparalleled depth, and are just fine trotting out youngsters Jered Weaver, Ervin Santana and Joe Saunders every fifth day. Then there's Jon Garland, acquired from the White Sox, who adds a veteran presence to help solidify that bunch. So take your time, Escobar and Lackey -- the rest of the Angels have the mound well-covered in Anaheim.
No. 3: New York Mets
There is nothing Santana can't do, no problem he can't solve. At least that's how it seems in Mets camp, where Santana alone has helped wash away all the sour memories of last season's collapse. Now there's reason for Mets fans to believe. Santana's presence has relieved Pedro Martinez -- perhaps this generation's most accomplished pitcher -- of his duties as an ace, and pushed 15-game winners John Maine and Oliver Perez into supporting roles. The Mets were without Santana last season and without Martinez for all but five starts, yet they still managed to finish fifth in the NL with a 4.40 rotation ERA. Improvement on that number seems all but guaranteed.
No. 2: Arizona Diamondbacks
This winter's trade for Haren could be the edge the D-backs needed to establish themselves as the class of the NL West. Now with two legitimate aces in Haren and Brandon Webb, the D-backs might boast the best starting duo in the Majors, let alone the division. Even if Randy Johnson can't begin to approach his Hall of Fame form, the summer should progress just swimmingly in Phoenix. If Johnson can, all the better for a rotation that finished third in the NL with a 4.23 ERA last season.
No. 1: San Diego Padres
The Padres led the Majors in ERA last season, and there's no reason to believe they can't do it again. The three keys to their rotation -- Jake Peavy, Chris Young and Greg Maddux -- are all back, and though some might expect a decline from Maddux at 42 years of age, the Padres aren't worried. Especially not when Young and Peavy, who combined for 28 wins and a 2.79 ERA last year, seemingly still have room to improve. Don't underestimate the addition of former rookie sensation Mark Prior, either. Though the odds of Prior making an impact remain low, his presence could pay significant dividends down the line.
Anthony DiComo is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.