Reigning debuts: Keuchel, Arrieta take mound

Defending Cy Young Award winners highlight slate full of aces

Reigning debuts: Keuchel, Arrieta take mound

The key storylines in both the Grapefruit and Cactus Leagues on Wednesday figure to center around the plethora of aces scheduled to take the mound.

For starters, fans across the globe can watch on MLB.TV as reigning American League Cy Young Award winner Dallas Keuchel makes his spring debut when the Astros host the Braves. The other key matchup in Grapefruit League action -- another of the eight games available Wednesday on MLB.TV -- will feature Mets ace Jacob deGrom making his first appearance of the spring in a Florida version of the Subway Series.

The Cactus League will be serving up its own share of elite pitchers out west, including the other reigning Cy Young winner and two high-profile starters looking to settle in with their new clubs.

Watch the action on MLB.TV

Here are some things to watch for throughout the day (all times ET):

Keuchel makes spring debut: ATL@HOU, 1:05 p.m., MLB.TV
Keuchel will take the hill, looking to build off his dominant campaign from a season ago. The southpaw went 20-8 with a 2.48 ERA, while tossing a pair of shutouts and leading the AL in both innings pitched (232) and WHIP (1.017).

The Braves, meanwhile, will counter with righty Julio Teheran, who is aiming for a bounceback season. Teheran racked up a 4.04 ERA in 2015, just one year after making his first All-Star appearance en route to posting a 2.89 ERA.

Keuchel on Opening Day start

deGrom, Nova square off in Big Apple battle: NYY@NYM, 1:10 p.m., MLB.TV
One day after Matt Harvey turned in a solid spring debut against the Braves, the Mets will hand the ball to their other co-ace in deGrom, as they take on the crosstown rival Yankees. The 27-year-old righty went 14-8 with a 2.54 ERA over 30 starts last season and currently has a 2.61 career ERA through his first two big league seasons.

Mets renew deGrom's contract

On the other side, Ivan Nova will make his latest push for a rotation spot in his second start of the spring. Nova, who missed the first 71 games last season while recovering from Tommy John surgery, went on to go 6-11 with a 5.07 ERA in 17 starts. He's competing with CC Sabathia for the final spot in the Yankees rotation.

Greinke on the mound for D-backs: SD@ARI, 3:10 p.m., MLB.TV
D-backs ace Zack Greinke will return to the mound for his second start with the club when Arizona welcomes the Padres to Salt River Fields. Greinke, who signed a $206.5 million deal this offseason, allowed just one hit over two scoreless innings in his spring debut last Friday.

The division-rival Padres will counter with 25-year-old righty Colin Rea, the club's top pitching prospect. Rea, who went 2-2 with a 4.26 ERA in six starts following his Aug. 11 debut, is battling for one of the two open spots in San Diego's starting rotation.

Greinke on his spring debut

Kazmir, Weaver face off in Freeway Series matchup: LAD@LAA, 3:10 p.m., MLB.TV
Former teammates Jered Weaver and Scott Kazmir will square off in a Cactus League adaptation of the Freeway Series. Kazmir, who spent parts of three seasons with the Angels from 2009-11, will make his second start of the spring after signing a three-year, $48 million deal with the Dodgers this offseason.

Weaver will also be making his second Cactus League start, having already tossed two scoreless innings against the Cubs last Friday. The veteran righty is looking to set the tone for a bounceback season after posting a 4.64 ERA last season, the highest in his 10-year career.

Cueto makes Giants debut: COL@SF, 3:05 p.m., Gameday Audio
Giants newcomer Johnny Cueto will make his highly-anticipated team debut, four days after he was originally expected to toe the rubber. San Francisco instead elected to push back Cueto's debut, citing his heavy workload last year as a member of the World Series-champion Royals.

Cueto, who signed a six-year, $130 million contract this winter, logged a total of 237 innings last year, including the postseason. The veteran righty is 64-38 with a 2.71 ERA over the last five seasons.

Outlook: Cueto, SP, SF

Arrieta debuts in duel with Kluber: CLE@CHC, 3:05 p.m., Gameday Audio
It will be a battle of Cy Young Award winners at Sloan Park when the Cubs host the visiting Indians. Reigning NL Cy Young Award winner Jake Arrieta is scheduled to get the start for the Cubs, while the Indians will counter with 2014 AL Cy Young winner Corey Kluber. In a rare twist, though both hurlers have already won a Cy Young Award, each enters the '16 season in search of his first All-Star appearance.

Arrieta seeking long-term deal

Gray set to make spring debut: OAK@CWS, 3:05 p.m., Gameday Audio
Yet another Cy Young hopeful will make his first appearance of the spring, as Oakland ace Sonny Gray will take the mound when the A's visit the White Sox. The 26-year-old righty went 14-7 with a 2.73 ERA over 31 starts last year en route to finishing third in AL Cy Young voting.

Paul Casella is a reporter for MLB.com. Follow him on Twitter at @paul_casella. This story was not subject to the approval of Major League Baseball or its clubs.