It might be Opening Day No. 4, but today -- and the rest of the week -- will start out with a big nod to No. 2. And that's no April Foolin'.

What's Next today? Oh, only the season premiere of the new-look Yankees and the new-look Astros, a baseball game between the two of them at Minute Maid Park and the first stop for the Derek Jeter Farewell Tour, or, in other words, what's sure to be a 162-game-long paean to one of the greats of all time in his last go-round.

"I've just tried to not look forward to everything being over," Jeter said recently. "If you call that soaking it in in Spring Training, I guess so. But I'm just trying to enjoy my time and not looking forward to it being over. That's the best way to put it."

The best way to describe what's going on with the Yankees starting today is renewed American League East hopes hinging on an infusion of fresh big-name talent in the lineup, courtesy of another offseason spending spree. We'll see Carlos Beltran and Brian McCann in pinstripes for the first time in a regular-season game, and if we're lucky, we'll also see Jacoby Ellsbury, who is getting over a Spring Training calf injury.

And on Friday in Toronto, we'll see the big league debut of Japanese pitching sensation Masahiro Tanaka, who was snapped up by the Yankees with a seven-year, $155 million deal after New York agreed to pay a $20 million posting fee to his former club back home, the Rakuten Golden Eagles. Tanaka has looked good this spring, and now's the time to answer the bell.

"He came in with an open mind about the plan we had here and how we do things, and he got on it right away," Yankees manager Joe Girardi said. "And he wanted to get on it right away. I think he's more prepared to do it right away than if he was to stick on more of his old schedule. I think he's much more prepared."

The Astros, who also play their first game tonight, should be more prepared for the season ahead now that they're acclimated to the AL and their division. The club is building for the future, but the addition of Opening Day starter Scott Feldman and outfielder Dexter Fowler, along with a stacked farm system led by outfielder George Springer -- who will open the season in the Minor Leagues but might not be there for long -- has them excited.

"It's extremely important to finish better than we did last year," second-year Astros manager Bo Porter said. "As an organization, we went through what we went through last year in order to take steps forward this year. It's extremely important for us to improve on the win-loss record, and that's what I said to the group early in camp: 'We should set out to be the most-improved team in Major League Baseball, from a win-loss standpoint.'"

After the Yankees and Astros become the last two teams in the big leagues to have lifted the lid on 2014, the rest of the week will be about settling into a rhythm and seeing what trends develop.

The well-traveled Dodgers, who are already 2-1 after a pair of victories over Arizona in Australia and an Opening Night loss to San Diego on Sunday, will get back into the swing of things today against the Padres at Petco Park, with Zack Greinke getting the ball for the first time this year.

The Tampa Bay Rays, a hot preseason World Series pick, will give the ball to Alex Cobb against Toronto tonight and hope that he provides much of what he did while being their best starter down the stretch last year.

On Wednesday, the 2013 AL Cy Young Award winner, Max Scherzer, is scheduled to pitch for the first time in 2014, going up against Royals left-hander Jason Vargas at Comerica Park, and also on that day, Cardinals fans will get their first look at last year's playoff wunderkind, Michael Wacha, as he begins the season as a staple of the St. Louis rotation with a start in Cincinnati. The fans -- and Reds hitters -- will also get a look at Wacha's new pitch, a cutter.

"The confidence level has definitely increased from throwing it in bullpens, throwing it warming up and then throwing it in these games for sure," Wacha said recently. "I can catch them off-guard with a different pitch."

Later in the week, more drama is certain to unfold. Weekend series will include fever-pitched divisional-rival matchups such as Dodgers-Giants, Braves-Nationals, White Sox-Royals and Cardinals-Pirates.

Not bad for the first week, right?