MLB's most interesting position battle received some unfortunate clarity right as spring training commenced.

The Boston Red Sox have two outfield slots to delegate between Shane Victorino, Mookie Betts and Rusney Castillo. While it was initially believed the veteran would make way for the younger talents, manager John Farrell said Victorino will start if healthy. 

That figured to leave Betts—a promising 22-year-old who hit .291/.368/.444 with the Red Sox last year—out of luck. But Castillo suffered a setback that places his Opening Day status in peril, per ESPNBoston.com's Gordon Edes: 

Castillo's injury takes away a top spring storyline, but there are several other key position battles to monitor. Let's take a look at three intriguing bouts after showcasing notable games kicking off spring training.

MLB.com offers the full schedule here.

Chicago Cubs: Third Base (Kris Bryant vs. Field)

Kris Bryant is the Chicago Cubs' best option at third base. Crowned MLB's top prospect by ESPN's Keith Law, the 23-year-old is more than ready for big league pitching after smashing his way to a .325/.438/.661 slash line last season.

Yet finances figure to delay his debut, even if just for a few weeks. Grantland's Michael Baumann explained how the Cubs will likely walk the league's service-time tightrope to wring out another year of their future star on the cheap. 

It’s widely accepted that even if Bryant proves this spring that he’s ready to break camp with the major league club, the Cubs will send him down to Triple-A for a few weeks. That’s because if, at the end of the 2020 season, Bryant has accrued six years of service time, he’ll be able to become a free agent, but if he’s accrued five years and 171 days of service time, he won’t, allowing the Cubs to control him for another year.

Facing a similar predicament last year, the Houston Astros waited until mid-April to unleash George Springer, who clubbed 20 homers in 78 games before suffering a quadriceps injury. Houston, however, harbored no playoff aspirations.

After signing Jon Lester, the Cubs are poised to at least factor into the postseason equation. An eagerness to mount their first winning campaign since 2009 makes this situation dicier, especially if Bryant forces their hand with a stalwart spring.

Remove service time, and it's an easy call. Anyone concerned about his swift transition to the majors will cite his 27.3 strikeout percentage last year. It's a fair fear, but his prime competition, Mike Olt, hit .160 last season with a 38.8 strikeout percentage.

The Cubs didn't let Javier Baez's whiffing tendencies deter them from letting the slugging middle infielder play 52 games last year despite batting .169/.227/.324 with a massive 41.5 percent strikeout rate.

Chicago has a bright future ahead, but it will knowingly send out a suboptimal Opening Day lineup in order to save some expenses.

Prediction: Olt starts; Bryant gets promoted mid-late April

Los Angeles Dodgers: Outfield (Joc Pederson vs. Andre Ethier)

Even after trading former MVP candidate Matt Kemp to the San Diego Padres, the Los Angeles Dodgers still have an outfield logjam to address. While the move seemed design to clear space for top prospect Joc Pederson, Andre Ethier is still hanging around.

Slated to earn $53.5 million over the next three years, per Cot's Baseball Contracts, Ethier became an unmovable asset after hitting .249/.322/.370 in 2014. Yet he's a career .285/.359/.462 hitter who justifiably does not want to settle for a bench role.

He told ESPNLosAngeles.com's Mark Saxon that sporadic playing time dampened his output last year.

I want the opportunity to play every day. My mind hasn't changed from when I told you guys that a couple months ago. I felt like when I get a chance to play every day, I put up the numbers they ask of me. For some strange reason, it just happened that coming off a good 2012 season, in 2013 they took games away. You start to wonder why that happened. I feel like if I get a good full year in and get the at-bats, it starts to add up. It's tough when you get 300 at-bats and you're expected to hit 15 or 20 home runs.

Pederson, however, is ready for the grand stage. He combated Triple-A last year, hitting .303/.435/.582 with 33 homers and 30 stolen bases. The batting average won't be pretty due to high strikeout tendencies, but he factors as an immediate 20-20 threat with strong plate discipline.

Perhaps most importantly, the Dodgers' new regime values defense. Kemp's bat caught fire last summer, but he still accounted for minus-12 defensive runs saved (DRS) in center field. Ethier would force Yasiel Puig over to center, but Pederson can provide a considerable defensive upgrade at center in the middle of the outfield.

Either way, remember that Scott Van Slyke devours southpaws, hitting .315/.415/.630 against them last season. Pederson, a lefty, will likely find himself in a platoon, with Ethier poaching some starts from Carl Crawford.

Prediction: Pederson (vs. righties)

Pittsburgh Pirates: Shortstop (Jordy Mercer vs. Jung Ho Kang)

Spring training means little in the grand scheme of things. Jake Fox once hit like Babe Ruth in March, only to evaporate come May. Heck, Mike Moustakas annually goads everyone into predicting a breakout season.

Yet it's hard not to take notice of Jung Ho Kang. Not only are most onlookers seeing the South Korean import for the first time, but he's competing for the Pittsburgh Pirates' starting shortstop gig with Jordy Mercer.

The 27-year-old made a fierce opening statement, belting an opposite-field blast in his first taste of MLB action. Take a look at his swing, courtesy of the team's Twitter page:

Having registering 40 homers for his native club last season, Kang certainly brings considerable power to the table, especially for a shortstop. Mercer can't compete there, but he's a known commodity who issued a dozen long balls and 2.0 wins above replacement (WAR) last year.

He's a more-than-capable starter, but Kang is the shiny new toy with mysteriously exciting upside. As an above-average defender, Mercer is also a better fit as a utility reserve who can snatch up playing time across the diamond, especially against lefties. 

If Kang falters, it won't take long for everyone to beat, "Don't blame me, I voted for Mercer" into the ground. Expect Kang to get a chance to run with the everyday role.

Prediction: Kang  

Note: All advanced statistics courtesy of FanGraphs.