Yoenis Cespedes and Yordano Ventura are both scheduled to take the field today as the defending NL and AL champions appear on MLB.TV for the first time this spring.
The last time most baseball fans saw either the Mets or Royals in action likely came last November, when Kansas City secured its first World Series title in 30 years. Today marks the first glimpse at the two reigning pennant winners since Kansas City recorded the Series-clinching out in Game 5.
• Watch the action on MLB.TV
It all starts at 1:10 p.m. ET, when Cespedes -- a focal point for much of the offseason and in the early stages of Spring Training -- leads the defending National League champion Mets into their Grapefruit League home opener. The action will continue on MLB.TV throughout the day, culminating in Ventura making his spring debut in Kansas City's nighttime showdown with the Padres.
As if that wasn't enough to look forward to, Friday's full slate of games will also feature a handful of the game's top aces toeing the rubber for the first time this spring.
Here are some things to watch for throughout the day (all times ET):
• Pennant-winning Mets play spring home opener: MIA@NYM, 1:10 p.m., MLB.TV
From re-signing Cespedes to the additions of Neil Walker and Asdrubal Cabrera to watching postseason hero Daniel Murphy sign with the rival Nationals, there has certainly been no shortage of storylines since the Mets' run to the World Series last October. The attention will be back on the field Friday, however, with the Mets set to play their Grapefruit League home opener.
• Cespedes, Mets set for home opener
Fans at Tradition Field -- and MLB.TV subscribers worldwide -- will be able to watch as Cespedes makes his spring debut against the Marlins. Walker and Cabrera are also both expected to make their Mets debuts.
• Reigning champs take field in prime time: KC@SD, 9:10 p.m., MLB.TV, MLB Network
Ventura had an up-and-down 2015 season, to say the least. Coming off a breakout 2014 campaign in which the righty posted a 3.20 ERA over 31 starts, Ventura found himself facing a demotion to the Minors after starting last year 4-7 with a 5.19 ERA through 14 starts.
An injury to fellow starter Jason Vargas, however, resulted in Ventura never actually making it to Triple-A Omaha. Instead, Ventura immediately returned to the Royals and proceeded to go 9-1 with a 3.10 ERA over his final 14 starts. The season ultimately ended with a World Series title, but now the champs are hoping the 24-year-old can take the next step this season -- something they had originally hoped he would do last year -- starting with Friday's spring debut against the Padres.

• Veteran southpaws square off in Astros home opener: STL@HOU, 1:05 p.m., MLB.TV
The Astros surprised many last year when they played their way into the club's first postseason berth since 2005. On the other hand, the Cardinals surprised almost nobody by earning their fifth straight postseason berth. The former division foes both have postseason aspirations for 2016, as they meet on Friday afternoon, when Wandy Rodriguez will make his first appearance in a Houston uniform since 2012, opposite Jaime Garcia and St. Louis.
Astros manager A.J. Hinch also mentioned earlier in the week that star middle infielders Jose Altuve and Carlos Correa could make their spring debuts in Friday's game.
• Greinke makes D-backs debut: OAK(ss)@ARI, 3:10 p.m., Gameday Audio
The D-backs made arguably the biggest splash of the offseason when they swooped in to sign ace Zack Greinke away from the rival Dodgers. Greinke, whose 1.66 ERA last year was the lowest since 1995, will make his D-backs debut Friday when Arizona welcomes the A's to Salt River Fields.
• Greinke set for highly anticipated D-backs debut
"Anybody that's been in this game -- it doesn't matter if the game doesn't even matter -- there's going to be some nerves," D-backs manager Chip Hale said. "So I'm sure he'll have some nerves going out there, and you're supposed to. But he's a pro and he knows how to handle it, and he'll get his work in."
• Kazmir dons Dodger blue for first time: LAD@TEX, 3:05 p.m. Gameday Audio
With Greinke departing to sign with the division-rival D-backs, the Dodgers responded by signing lefty Scott Kazmir to a three-year, $48 million deal. Kazmir, a three-time All-Star, had previously spent each of his first 11 big league seasons in the American League, most recently splitting his time between the A's and Astros last season.
• Kazmir ready to begin new chapter with Dodgers
• Bumgarner set to ace first spring test: SF@CIN, 3:05 p.m., Gameday Audio
Perennial NL Cy Young Award candidate Madison Bumgarner will toe the rubber for the first time this spring when the Giants travel to Goodyear to take on the Reds. The 26-year-old lefty is coming off back-to-back sub-3.00 ERA seasons, tallying a 2.95 ERA to go along with eight complete games and four shutouts in that span.

• Verlander looks to build off strong finish: NYY@DET, 1:05 p.m., Gameday Audo
Though Verlander has struggled to look like himself at times over the past few years, the 33-year-old righty showed flashes of his former AL Cy Young Award-winning form down the stretch last season. Verlander, who has already been named Detroit's Opening Day starter, didn't make his season debut until June 13 last year, then racked up a 5.05 ERA over his first nine starts. He managed to eventually flip the switch, however, posting a dominant 2.12 ERA over his final 11 outings. The Tigers will be hoping the latter Verlander shows up in 2016, starting with Thursday's spring debut against the Yankees.
• Verlander embracing mentor role
• Archer, Rays take on AL East rival: TB@BOS, 1:05 p.m., Gameday Audio
Fresh off his first All-Star campaign, Rays ace Chris Archer will take the hill Friday for his spring debut against the Red Sox. Archer finished with a 3.23 ERA to go along with 252 strikeouts over 212 innings. The 27-year-old now has a 3.33 career ERA through 95 outings, though he is just 1-6 with a 5.14 ERA in 11 regular-season starts against Boston.