The first significant trade of the offseason went down Monday night, as the New York Yankees acquired left-hander James Paxton from the Seattle Mariners for three prospects, most notably left-hander Justus Sheffield. MLB.com currently ranks Sheffield as the 31st best prospect in baseball. The Yankees got their starter and the Mariners continued their rebuild.

In a normal offseason, acquiring a pitcher of Paxton's caliber would qualify as "the big move," but this is not a normal offseason for the Yankees. They had a 100-win season in 2018 but it still felt like a disappointment because they were quickly ousted by the rival Boston Red Sox in the ALDS. The Yankees also stayed under the $197 million luxury tax threshold and reset their tax rate.

In theory, the Yankees are motivated to improve their roster after getting shown up by the Red Sox, and, again in theory, they have lots of money to spend after resetting their luxury tax rate. The team denies the former is motivating their offseason moves -- what else are they supposed to say? -- and who really knows whether the latter is true. I do know the Yankees added Paxton though, and that's significant.

"I can't predict what's going to happen as we move forward, other than the fact that we need to fill some needs," said Yankees GM Brian Cashman during a conference call Monday night, following the Paxton trade.

Even after acquiring Paxton and re-signing both Brett Gardner and CC Sabathia, the Yankees still have several roster needs to address, and Cashman made it pretty clear his work is far from done this offseason. Where do the Yankees go from here? Let's break it down.

Add another starter

MLB: Arizona Diamondbacks at Colorado Rockies
The Yankees are still pursuing Patrick Corbin even after acquiring James Paxton. USATSI

Yes, the Yankees still want another starting pitcher. Cashman said he wanted to add two high-end starting pitchers after re-signing Sabathia, and Paxton counts as the first. Now he's looking for one more. The team's rotation currently lines up like so:

  1. Luis Severino
  2. James Paxton
  3. Masahiro Tanaka
  4. ???
  5. CC Sabathia

The Yankees do still have Sonny Gray on their roster, but he is as good as gone. Gray has struggled in New York and Cashman has made it clear he will be traded at some point. It's not a matter of if he'll be traded, but when.

Anyway, even with Paxton on board, the Yankees remain connected to free agents Patrick Corbin and J.A. Happ, both of whom would slot nicely into that open rotation spot. Cost could be an issue with Corbin -- the Yankees have about $25 million to spend under next year's $206 million luxury tax threshold -- but the interest is real. 

Point is, the Yankees want -- and need -- another starting pitcher. Gray didn't work out and Jordan Montgomery is still rehabbing from Tommy John surgery. Others, like Domingo German and Jonathan Loaisiga, fit best as depth arms, not opening day rotation members. And, given their continued interest in Corbin and Happ, the Yankees want a very good starter to fill out their staff, not a back-end innings guy.

Replace Gregorius

The Yankees kicked off their offseason with bad news. Shortstop Didi Gregorius needed Tommy John surgery -- he hurt his elbow at some point during the ALDS, the team acknowledged -- and will miss an undetermined length of time in 2019. He could be back in May, or June, or September. No one is sure yet.

Because of that, the Yankees need to add a middle infielder this offseason. Gleyber Torres can play shortstop or second base, which gives the team more options. They don't have to replace Gregorius with another shortstop. They can get a second baseman and slide Torres over to short. That said, they did ask about Jean Segura during Paxton trade talks:

Segura has become an excellent two-way player and would've been a more than capable fill-in for Gregorius not only in 2019, but beyond given the fact Gregorius will become a free agent next winter. I suppose the Yankees and Mariners could revisit their Segura trade talks later in the offseason.

Of course, the big name free agent shortstop on the market is Manny Machado, whom the Yankees did try to acquire at the trade deadline. Machado would replace Gregorius at shortstop in the interim and then presumably move back to third base once Didi returns, with the defensive deficient Miguel Andujar moving to first base or perhaps the outfield.

The Gregorius injury created an obvious opening for Machado, but Machado is someone you make room for anyway. Gregorius getting hurt didn't increase the likelihood of the Yankees signing Machado. A $300 million decision is never going to be based on another player getting hurt. The Yankees will sign Machado if the price is right. That's all. They won't drop $30 million a year (likely more) on Machado just because Gregorius is hurt.

Aside from Machado, the remaining group of free agent shortstops is highlighted by all glove/no bat types like Jose Iglesias, Adeiny Hechavarria and Freddy Galvis. The crop of free agent second basemen is more appealing. Asdrubal Cabrera, Brian Dozier, Marwin Gonzalez, DJ LeMahieu and Jed Lowrie are all available. The Yankees have some options here. Now they just have to go out and actually get someone.

Bolster the bullpen

MLB: ALDS-Boston Red Sox at New York Yankees
The Yankees have to replace free agent reliever David Robertson this offseason. USATSI

The Yankees boast an impressive bullpen even with David Robertson and Zach Britton becoming free agents. Aroldis Chapman is locked into the ninth inning with Dellin Betances, Chad Green and Jonathan Holder setting him up. Not many teams could potentially lose Robertson and Britton and still have a dominant end-game unit like the Yankees.

That said, Cashman & Co. clearly value a deep bullpen. That's why they went out to get Britton despite having Chapman and Betances and Green and Robertson. There is no such thing as too many good relievers and it stands to reason they'll look to replace Robertson and Britton this offseason, or at least one of them.

At the moment, New York's eight-man bullpen looks like this:

Kahnle struggled last year and Tarpley has nine September call-up innings to his credit. There's room for another high-quality reliever in there, for sure. The Yankees could simply re-sign Robertson or Britton, or pursue one of the many other relievers on the free agent market, like Jeurys Familia, Kelvin Herrera,  Andrew Miller and Adam Ottavino.

It's clear the Yankees need another starter and a Gregorius replacement. The bullpen is a sneaky high priority too. Don't be surprised if New York finds a way to bring in two relievers this offseason -- sign one and trade Gray for another? -- to maintain that bullpen depth. Paxton, Tanaka and Sabathia aren't known for pitching deep into games. The bullpen will be a priority.

What about Harper?

Similar to Machado, signing Bryce Harper is a decision that will be made independent of everything else. If the numbers make sense, the Yankees will sign him and figure out the rest later, even if it means playing Harper at first base.

The Yankees do have a recent history of late offseason big ticket signings that take them over the luxury tax threshold. Cashman talked owner Hal Steinbrenner into signing Mark Teixeira in December 2008, after the team committed nearly $250 million to Sabathia and A.J. Burnett. He also convinced him to sign Tanaka in January 2014 after committing nearly $300 million to Carlos Beltran, Jacoby Ellsbury and Brian McCann.

I get the sense that, if the Yankees do sign Harper, it'll go down similarly to Teixeira and Tanaka. The Yankees will handle their offseason business (sign another starter, replace Gregorius, add a reliever or two) then make that last-minute decision to swoop in and sign Harper, assuming he's still out there. And he probably will be. Scott Boras historically waits out the market with his top clients. Prince Fielder, Max Scherzer and J.D. Martinez didn't sign until later in the offseason, remember.

Machado seems to be the priority over Harper because he fits the roster better as a Gregorius replacement and someone who could push Andujar to less defensively demanding position. The Yankees already have a full outfield and would have to push someone, possibly Harper, to first base to make Harper work with the roster. That's a minor detail though. Harper and Machado are elite talents and if the numbers work for the Yankees, they'll pounce ... eventually.

The Yankees have been one of the most active teams early this offseason. They re-signed Gardner and Sabathia in recent weeks and hauled in Paxton this week. There's still plenty more to do though. The Yankees still need one more starting pitcher, they have to address their middle infield in the wake of the Gregorius injury and they're going to do something to bolster the bullpen. Maybe multiple somethings. The Yankees have been busy already and there's no reason to think they're going to slow down.