DeGrom struck out the side in the third inning and fanned six batters in total before he appeared to hurt himself during an at bat in the bottom of the third inning.
Callaway, formerly the pitching coach with Cleveland, said he's never had a pitcher suffer a hyperextended elbow. New York's hopes of remaining in contention the remainder of the season could hinge on the results of the MRI performed on deGrom late Wednesday night.
Soroka was a first-round pick by Atlanta in 2015 and quickly rose through the minor league ranks.
NY has lost seven straight games in which they've scored three runs or less.
DeGrom has thrown 18 1/3 consecutive scoreless innings and seemed in control against the Braves, striking out four straight at one point and lowering his ERA to 1.87.
After scoring 14 runs on Sunday, the Mets have tallied single runs in two of the first 18 innings in this series.
Yoenis Cespedes snapped his glitzy necklace during a hard slide into second base in the first inning, scattering gems around the infield. Jay Bruce's eight-game streak ended with an 0-for-3 showing.
Another is that with Wednesday's loss, the Mets fell out of first place. The 28-year-old lefty is 4-0 with a 2.25 ERA this season going into this start at home against Los Angeles.
White Sox righty Reynaldo Lopez hasn't given up more than two earned runs in any of his five starts this season, and sports a nifty 1.78 ERA. "But at the same time, when you look back and see this kind of stuff where they're blatantly not strikes, I just can't sit back and let it go anymore".