The first goal when teams report to Spring Training in February is to earn a spot in the postseason. For the teams that accomplish that in September, the first hope for October is to begin the playoffs with a full complement of healthy players.
Naturally, it doesn't always work out that way. And this season there seem to be question marks -- some because of injury, some because of other factors -- attached to an uncommon number of integral players going into the march to crown the next World Series champion. Which just adds another layer of drama to what is already a tension-filled time of year.
Everything is magnified in the postseason. Winning and losing can hinge on so many factors -- this year, more than ever, considering which players may be available and what condition they're in.
Here's a look at a few concerns some of the World Series hopefuls are grappling with:
Dodgers: For more than two months this summer, the Dodgers were not only the best team in baseball, they were historically hot, going 53-13 at one stretch. And that turnaround coincided roughly with the arrival of sensational rookie outfielder Yasiel Puig.
Going into the final weekend, though, the Dodgers had lost 13 of 21 games. It probably isn't coincidental that Puig has been battling a painful hip injury and batted just .211 in those games. But it's not just him. Outfielder Andre Ethier (sprained ankle) is questionable for the start of the Division Series. Shortstop Hanley Ramirez has been fighting nerve irritation in his back and a tight left hamstring. Outfielders Carl Crawford and Matt Kemp have been hurt, too.
On paper, the Dodgers have a surplus of outfielders. On the field may be a different story.
"Hopefully I have that problem," manager Don Mattingly said. "I'd like to have that problem to deal with. I'd just like to get them all back and know they are healthy."
Tigers: Detroit has had trouble scoring runs at times this season. That makes defending Triple Crown winner Miguel Cabrera's status so crucial. One of the best hitters on the planet has been bothered since the middle of the schedule by abdominal and groin strains. And it's not likely he'll be even close to 100 percent during the postseason.
"Hopefully I can produce," he said. "It's something I have to live with right now. In the offseason, you rest. Right now, you work."
Adding to the intrigue is the announcement that shortstop Jhonny Peralta will return Friday night -- as a left fielder. The Tigers can use his bat, but it remains to be seen how sharp he'll be after serving his 50-game Biogenesis-related suspension. Dave Dombrowski cautioned that it's not a given that Peralta will be on the American League Division Series roster.
"We think it's best to give him this opportunity," the team president and general manager said. "But I'm not making any proclamations about postseason rosters at this time, because we've not had those discussions."
The Tigers are also hoping that relievers Bruce Rondon and Phil Coke will be healthy enough to help shore up the bullpen.
Cardinals: St. Louis seemed to catch a break when Allen Craig's left foot injury turned out to be a strain instead of a fracture -- except that he's still not back, and there is no clear indication of when he might be. Also, Matt Holliday missed three games earlier in the week with back tightness, which has been a recurring problem throughout his career.
Then there's closer Edward Mujica, who was taken out of that role earlier this week. There have been no announcements that there's a physical explanation for his recent ineffectiveness, but bullpen-by-committee is hardly an ideal scenario going into the playoffs.
"A week away from October you don't want to have to be rethinking your club all of a sudden," said general manager John Mozeliak philosophically. "But sometimes you do. You make adjustments or you go home."
Braves: Outfielder Jason Heyward is back after suffering a broken jaw when hit in the face by a pitch on Aug. 21. In his first five games back, though, he managed just two singles in 15 at-bats. It's not surprising that he's rusty after a long layoff, but it remains to be seen whether he can get his eye back by the time the playoffs begin. He went 5-for-5 in Thursday night's win over the Phillies, which is obviously a good sign.
Red Sox: Speedy leadoff man Jacoby Ellsbury returned to the lineup Wednesday night for the first time since Sept. 5. He'd been sidelined by a compression fracture in his right foot.
"He can impact a game, obviously, as soon as he gets on base," manager John Farrell said. "It's a threat. Every pitch that's thrown, he's got the potential to steal."
Athletics: Yoenis Cespedes had a cortisone shot to relieve tendinitis in his sore right shoulder a week and a half ago. He's played at DH but hasn't been in left field since Sept. 13.
"We want him in the outfield, and we want him to throw," manager Bob Melvin said.
• The Rangers, still clinging to Wild Card hopes, are monitoring the health of ace right-hander Yu Darvish. And suspended slugger Nelson Cruz, a potential free agent, is eligible to return.
• Jason Grilli, one of baseball's best stories early in the season, earned his first save in two months for the Pirates on Saturday night after returning from a forearm injury.
• Right-hander Jesse Crain (shoulder) had been activated by the Rays but hasn't pitched since being acquired from the White Sox on July 29.
• Indians center fielder Michael Bourn hasn't started the Tribe's last three games with a sprained wrist. And right-hander Justin Masterson, who has 14 wins, hasn't started since Sept. 2 with a strained oblique; he came out of the bullpen Wednesday night.
• The Reds still haven't decided whether lightning-fast outfielder Billy Hamilton will be on the postseason roster.
Paul Hagen is a reporter for MLB.com.