On Tuesday, the Yankees added a new second baseman in a trade with the Cubs. New York acquired Starlin Castro in a deal that sends right-hander Adam Warren and a player to be named later to Chicago. Both teams have announced the trade.

For the Yankees, this move is the latest in a string of deals aimed at getting younger over the last 13 months or so. Here's a quick timeline:

December 2014: Acquired Didi Gregorius for Shane Greene.
December 2014: Acquired Nathan Eovaldi (and others) for Martin Prado and David Phelps.
July 2015: Acquired Dustin Ackley for Ramon Flores and Jose Ramirez.
November 2015: Acquired Aaron Hicks for John Ryan Murphy.
December 2015: Acquired Castro for Warren and a player to be named.

Ackley is the oldest of the five players the Yankees acquired in those trades at 27. Hicks is 26, Castro is 25, and both Eovaldi and Gregorius were 24 at the time of their deals.

All five of those players have some things in common: They're all very talented -- all five appeared on at least one Baseball America top-100 prospects list -- they've all had some struggles at the MLB level, and they were all deemed expendable by their former clubs. New York swooped in to acquire change-of-scenery guys.

The Yankees also dipped into their farm system more often in 2015, most notably calling up Greg Bird and Luis Severino in the second half. They also called up others like Slade Heathcott, Rob Refsnyder and a slew of relievers. It's been a long time since the farm system was Plan A whenever a need arose.

This is the Yankees' version of a rebuild. They're never going to tear it down completely like the Astros did or the Braves are doing right now. The New York market doesn't allow that. Instead they're rebuilding on the fly, adding young talented players when possible, and dipping into their farm system.

“We can't rebuild here," said team president Randy Levine to Newsday's Brian Heyman Tuesday. "That's not what we're about, our fan base. We're trying to win every year and we're trying to get younger and transition. Most teams, they have two, three, four years to rebuild. We don't do that."

The Yankees went 87-75 this past season and did go to the postseason -- albeit as a wild-card team -- in what could be considered a retooling year. Maybe transitional year works better. Gregorius and Eovaldi paid dividends, as did Ackley after his midseason trade. The young additions helped them get to October.

The process doesn't stop there. Hicks and now Castro have been brought aboard this winter, and next season Severino and Bird will be asked to play bigger roles. Top prospect Gary Sanchez could also step in to replace Murphy as Brian McCann's backup. The Yankees are an old team, but they're making an effort to get younger. They're just not doing it with a full tear down.

“The fact that we are rebuilding, all these young players being introduced while we're being competitive -- we were a game from going on -- I think that's very hard to do," added Levine. "I think it's a real accomplishment."

Starlin Castro is the latest piece of New York's on-the-field rebuild.
Starlin Castro is the latest piece of New York's on-the-field rebuild. (USATSI)