There are certainties, of course. Players will say they're in the best shape of their lives, pitchers will test new pitches, there will be sore limbs and achy bones and early pitch-count limits and the dreaded PFP (pitchers' fielding practice) drills on those early back-field mornings.
But there are many questions in a sport that's already unpredictable, and a few of the biggest ones will start to be answered this week, such as:
1. How 'bout those champs?
The Boston Red Sox, otherwise known as the team everyone wants to -- and has to -- be better than to wind up as the last one standing at the end of October, are heading to Fort Myers, Fla., with a crown to defend, and they're doing it with a different cast.
Boston didn't make any huge waves this winter, preferring to make minor adjustments to its championship roster here and there. We'll begin to see if it works.
Outfielder Jacoby Ellsbury is gone to the Yankees, of all teams, leaving young Jackie Bradley Jr. or Minor League signee Grady Sizemore to earn the big time in center field. Catcher Jarrod Saltalamacchia signed with the Marlins and was replaced by a different veteran free agent, A.J. Pierzynski.
Xander Bogaerts, all of 21 years old and fresh off valuable playing time in the 2013 postseason, will play every day somewhere, whether it's shortstop or third base. Last year's shortstop, Stephen Drew, remains a free agent.
The Red Sox have Jon Lester, Clay Buchholz, Jake Peavy and John Lackey heading up a strong and deep starting rotation, and general manager Ben Cherington has sounded confident all winter that it, like the rest of his team, doesn't need to be altered much.
"We're very comfortable not doing anything," Cherington said. "We all know that with starting pitching, a supposed surplus has a way of working itself out usually."
2. Will the Yankees' offseason shopping spree pay off?
OK, so they signed Ellsbury, Masahiro Tanaka, Brian McCann and Carlos Beltran ... and let's not forget Brian Roberts, Kelly Johnson and Matt Thornton.
In other words, they're all-in once again, their supposed payroll limitations didn't seem so limited, and expectations are huge in the Bronx after an 85-77 season that saw them miss the playoffs for the first time since 2008.
Now, how will it all come together? And will a healthy Derek Jeter be a major part of it?
"I've been working hard, and I've had a complete offseason to work out and strengthen everything," Jeter said. "So I feel good right now. ... We still have six weeks of Spring Training. The goal is to be ready Opening Day, not the first day of Spring Training, so you kind of pace yourself."
3. Can one player change everything for one team?
This is not to suggest that Seattle thinks at all that its 10-year, $240 million commitment to the best player on the open market, Robinson Cano, needs to result in a World Series championship right away to make it all worth the investment.
But with Cano and the other additions GM Jack Zduriencik and new manager Lloyd McClendon have brought to Seattle (Corey Hart, Logan Morrison, Fernando Rodney, Scott Baker and possibly more on the way) to join up with aces Felix Hernandez and Hisashi Iwakuma and an exciting group of very young players that includes starters Taijuan Walker and James Paxton and catcher Mike Zunino, this team will be expected to improve dramatically this year.
And it all starts this week in Peoria, Ariz.
"[There have been] a lot of positive developments and influences," Zduriencik said. "The players see that we're doing it right and it makes them think positively. It has impact."
4. Where will Ubaldo Jimenez and Ervin Santana (and quite a few others) end up?
The top two pitchers remaining on the free-agent market still don't know where they're headed, and the first drills start later this week. They're not the only ones looking for new homes.
Position players Drew, Nelson Cruz, Kendrys Morales, Placido Polanco and Juan Pierre are still out there, as are closers Joel Hanrahan, Andrew Bailey, Rafael Betancourt and Kevin Gregg, righty relievers Ryan Madson, Frank Francisco, Matt Guerrier, Brett Myers and lefties Mike Gonzalez and Oliver Perez, among others.
A key late signing here or there could make those Spring Training rosters look a whole lot different.