The Yankees will find themselves trying to serve two masters yet again in 2016. General manager Brian Cashman wanted a younger roster, and he's got it, with pair of 25-year-old middle infielders, a 21-year-old potential ace and a dynamic fourth outfielder with All-Star upside. (Not to mention perhaps the best closer in baseball, who's just 27.)

But the Yankees are still old.

There's no telling if Alex Rodriguez and Mark Teixeira can repeat their resurgent 2015 campaigns or if center fielder Jacoby Ellsbury and left fielder Brett Gardner can bounce back from rough seasons. Right now, there are more questions than answers in the Bronx.

With spring training officially under way starting this Thursday, below are the 10 biggest Yankees storylines heading into 2016.

1. Alexander Enmanuel Rodriguez

A-Rod remains one of the most interesting cases in baseball. Can he, at age 40 and on two surgically repaired hips, hit 27 home runs and catch Babe Ruth in career homers? He will be the full-time designated hitter in 2016. If the Yankees are to see October, he needs to produce in the lineup's cleanup spot.

2. The (historic?) bullpen

It's supposed to be historic. Will it? The three-headed monster of Dellin Betances, Andrew Miller and Aroldis Chapman is, on paper, maybe the best in baseball. But Chapman may be suspended, and injuries are always a factor. But if they stay on the field all year? They'll shorten an awful lot of games.

3. Joe Girardi: Hot seat?

Girardi is signed through 2017, and he's taken the team to the postseason in five of eight seasons, including a World Series in 2009. But the fact remains: the Yanks haven't won a playoff game since 2012. If they sputter to 74 wins this year, might it be the beginning of the end for Girardi?

4. Bounce-back

Third baseman Chase Headley had 23 errors in 2015. Jacoby Ellsbury was so bad by the end of the year he was benched in the Wild Card game. Brett Gardner hit .206 in the second half. Can those three--earning a combined $257 million--bounce back this year?

5. Didi Gregorius's Sophomore Season

What will Gregorius do for an encore? The 25-year-old Derek Jeter heir was the second-best defender in the AL last season and finished the year hitting .267 with nine home runs. Not bad for a nine-hole hitter. Is a Gold Glove or All-Star appearance in his immediate future?

6. Starlin Castro: Bargin or bust?

The Cubs seemingly couldn't wait to replace Castro--a three-time All-Star who's just 25 years old--with graybeard Ben Zobrist in November. The Yankees were quick to hop on Castro, whom they believe still has his best years ahead of him.

It's rare that a high-profile player comes to New York and switches position (in Castro's case, going from shortstop to second base) and faces less pressure. But the Yankees are banking on that to help him bolster the bottom of their order.

7. The Walking Wounded

Too many Yankees suffered serious injuries to in 2015 to list here. But among them, they need Ellsbury (knee), Gardner (wrist) and Teixeira (leg) to produce full, strong seasons. Then there's the starting rotation, who has a health question mark at every spot. The Yankees would be thrilled to finally get a full season out of right-hander Masahiro Tanaka, who's experienced arm issues in each of his first two seasons in the Bronx.

8. Crafty Cashman

Cashman isn't afraid to deal at the trade deadline. He stayed put in 2015, choosing to stick by the organization's top young talent rather than sacrificing it to improve the roster. But if the Yankees are overachieving, might he consider parting with a top chip or two to get what the big-league club needs? Or will the untouchable prospects stay that way?

9. AL East Parity

Who's going to win the division? Who knows. Only the Red Sox have seemed to greatly improve their team over the offseason. But Boston had lots of work to do and it's unclear whether new general manager Dave Dombrowski has turned them into a no-doubt contender. The Orioles look decent. The Rays look stronger. And the Blue Jays look like they'll score a ton of runs and cross their fingers they don't give up too many.

10. Back to the Future

In 2016, the Yankees could see the arrival of a batch of prospects they expect to be around a long time. Hulking right fielder Aaron Judge, 23, seems a few tweaks away from major-league ready. Shortstop Jorge Mateo, 20, could be considered as a September pinch-running candidate--he might be the fastest player in the minors. And 2015 first-round pick James Kaprielian, a 21-year-old right-hander, hasn't done anything to take himself off the fast track to pinstripes.

Ryan Hatch may be reached at rhatch@njadvancemedia.com. Follow him on Twitter @ryanhatch. Find NJ.com on Facebook.