Trade Gregorius for Bellinger? Seager and Bird are both injured.

Don't blow it off.

Corey Seager
Position: Shortstop
Bats: Left • Throws: Right
6-4, 220lb
Team: Los Angeles Dodgers (majors, 10-day DL)
Born: April 27, 1994 (Age: 24 and 5 days) in Charlotte, NC
2016 NL RoY
1,528 PA, 132 OPS+

Dodgers star shortstop Corey Seager has a UCL sprain in his right elbow and needs Tommy John surgery. Seager will miss the remainder of the 2018 season.

Cody Bellinger
Positions: First Baseman and Leftfielder
Bats: Left • Throws: Left
6-4, 210lb
Team: Los Angeles Dodgers (majors)
Born: July 13, 1995 (Age: 22 and 293 days)
670 PA, 139 OPS+
2017 NL RoY; 39 home runs in 480 at bats

Bellinger was removed from a April 29, 2018 game in San Francisco for not running out a batted ball. There had been a previous incident in another game. Bellinger hit his fourth homer May 1. Bellinger may still be in the dog house.

Greg Bird
Position: First Baseman
Bats: Left • Throws: Right
6-4, 220lb
Team: New York Yankees (majors, 10-day DL)
Born: November 9, 1992 (Age: 25 and 174 days)
348 PA, 109 OPS+

Bird has not played in 2018 and has missed the entire 2016 season and considerable time in 2015 and 2017. Bird has been injury prone.

Didi Gregorius
Position: Shortstop
Bats: Left • Throws: Right
6-3, 205lb
Team: New York Yankees (majors)
Born: February 18, 1990 (Age: 28 and 73 days)
2,594 PA, 100 OPS+
2018: 206 OPS+, leads AL in HR, RBI, SLG, OPS

Gregorius will never be worth more.

Why would the Dodgers do it?

Both the Dodgers and Yankees are built to win now. The injury to Corey Seager puts the Dodgers in jeopardy not only in 2018 but also in 2019. Plus, who knows if Seager's throwing arm will be strong enough to play shortstop. They could also slide Seager over to second base.

If the Dodgers have soured on Bellinger, they might just consider it.

Why would the Yankees do it?

The Yankees are playing highly regarded rookie shortstop Gleyber Torres at second base. Torres could return to his natural position of shortstop. The Yankees also have veteran second baseman Neil Walker and Brandon Drury, who plays both third and second. Drury is due to return from migraine headaches. The Yanks also have shortstop Tyler Wade.

Bellinger might hit 300 home runs in the next decade. Gregorius could return to his league average batting, especially if the league stops using Titlist baseball. The Yankees need reliable lefty power, which Greg Bird is not supplying.

What about Manny Machado?

Baltimore shortstop Manny Machado (Age: 25 and 300 days) will be a free agent after the 2018 season and is playing shortstop full time for the first time in his seven year career.
2018 212 OPS+; leads AL in BA, OPB, OPS+, TB

Machado is hitting even better than Gregorius. Machado is being paid $16 million in 2018. Gregorius will be a free agent in 2020 and is being paid $8,250,000 in 2018 and can get arbitration in 2019.

Interesting proposal. It's very unlikely that Yankee general manager Brian Cashman would come up with this. The Dodgers would pretty much have to force it on him.