Sometime around mid-May, those best-laid plans have typically already been scrapped.
The reason? Injuries.
They affect every team, but it seems as though some clubs cope better than others. The Phillies have struggled through the first three months with significant injuries to three of their stars -- Chase Utley, Ryan Howard and Roy Halladay. Meanwhile, the Yankees are without their Hall-of-Fame-bound closer, Mariano Rivera, and now are down three starting pitchers. They have the second-best record in baseball.
There are plenty of theories as to why some teams seem better-equipped than others when the injury bug hits. Organizational depth, hot pitching, the team's post-injury mindset and luck all play major factors.
Dodgers manager Don Mattingly has always been one to point to depth. He has said some of the most important acquisitions a general manager makes are the ones that go unnoticed until midseason, when a key hitter -- like Dodgers All-Star center fielder Matt Kemp -- goes down.
"You've got to find a way to win a game today, that's where we're at," Mattingly said Thursday. "We've got to band together, play some baseball, play our best baseball, find a way to win a game, get to the [All-Star] break and get our guys back. It doesn't matter who I have in there, I'm trying to put the best lineup possible out there, and that's it."
For much of the season the Dodgers seemed to be weathering the storm. When Kemp went down with a hamstring injury, he was one of four members of the Opening Day lineup to be placed on the disabled list during a two-week span in mid-May. That's when Los Angeles' role players and Minor Leaguers began to make their marks. Scott Van Slyke hit a game-winning three-run home run against the Cardinals. Ivan DeJesus hit a two-run ninth-inning double to help the Dodgers come from behind in Arizona.
Recently, however, those injuries have seemingly overwhelmed Los Angeles, which has lost five in a row and nine of 10. The Dodgers found out the hard way that, in terms of dealing with injuries, the biggest factors are the number of injuries, the length of time a player is out, and which players are hurt.
For a short period, however, all it takes to cope with injuries is the right mindset in the clubhouse. Yankees left-hander Andy Pettitte, who recently broke his fibula near his left ankle and will be sidelined for at least eight weeks, laid out what that mindset looks like.
"We've just got to weather the storm," Pettitte said. "Nobody's going to feel sorry for you with injuries and stuff like that. We've got a lot of good stuff going on here. We've got plenty of guys who can step in and do the job, so it's time to put my pom-poms on and be a cheerleader now for six weeks or so."
Earlier this month, Phillies manager Charlie Manuel pointed to the mentality of players tasked with taking over for the injured regulars.
"We have guys on our team from the Minor Leagues," Manuel said. "Let me tell you something -- they look and they see Chase Utley and Ryan Howard and Halladay, and they know those guys are coming back. And they want to stay on the team. And staying on the team is probably more important for them now than going out and performing and winning the game. They want to do something good. And they might be tense. That's where the pressure comes in."
That's why, as the theory goes, having the best bench players isn't as important as having the right bench players. For the Dodgers this season, one of the right role players has been Bobby Abreu.
Initially signed to be a veteran bat off the bench, Abreu has become a regular in Mattingly's starting lineup because of injuries. Utility man Jerry Hairston Jr. pinpointed why.
"People don't realize how, when you lose a hitter like Matt Kemp, you don't just plug in guys in the third and fourth holes," Hairston said. "Bobby's done it his whole career. He's allowed guys to hit in positions where they're more comfortable. He's also helped a lot of guys -- myself included -- with the way he goes about his at-bats."
The Dodgers needed a middle-of-the-order bat. Waiting on the bench was Abreu.
Similarly, in San Francisco, the Giants needed a shut-down arm in the ninth inning to take over for injured closer Brian Wilson. Santiago Casilla stepped right in.
In New York, the Mets needed a center fielder who could force the issue offensively when Andres Torres was hurt in April. Kirk Nieuwenhuis filled in, and although Torres is back, Nieuwenhuis is still playing a vital role.
There is almost nothing teams can do to prevent the injury bug's arrival. As a result, damage control is often the most appropriate response.
That almost always starts with having the right players in place long before those fateful injuries occur.
AJ Cassavell is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs. This story was not subject to the approval of Major League Baseball or its clubs.