NEW YORK -- Mets closer Edwin Díaz suffered another blow in a difficult season on Thursday, when a 100-mph Manny Machado comebacker struck him in the left foot. Although the line drive forced Diaz from the Mets’ 4-0 win over the Padres at Citi Field in the ninth inning, he appears to have avoided the worst: X-rays taken immediately after the game came back negative.

“A glancing blow off the big toe,” was how Mets manager Mickey Callaway described it. “It was a little sore, so we decided we didn’t want him to make any pitches where he had to kind of brace his delivery with that foot.”

Leading off the ninth inning, Machado hit a comebacker that struck Diaz before skipping into the outfield for a single. Following a brief conference with Callaway and trainer Brian Chicklo, Diaz walked off the field under his own power, with Luis Avilan coming in to relieve him.

Diaz was busy receiving treatment after the game on Thursday, and thus was unavailable to address his situation. The Mets will know more, including whether he will be able to avoid the injured list, by Friday afternoon. For now, he is day to day.

“If he’s sore and trying to balance himself and brace himself on that foot, it might change his mechanics,” Callaway said.

If Diaz misses any time, Seth Lugo and Jeurys Familia would be the top candidates to replace him in the ninth inning. The Mets could also mix in left-hander Justin Wilson based on matchups.

Regardless of how much -- if any -- time Diaz misses, consider it another mild setback in a disappointing summer for the closer. In his first season with the Mets, Diaz is 22-for-26 in save opportunities with a 4.81 ERA. A source said this week that the Mets are open to trading Diaz prior to the July 31 Trade Deadline, though they would need such a significant haul in return that it’s highly unlikely they consummate a deal.

“I don’t really have a reaction to it,” Diaz said of the rumors on Wednesday. “My job is to go on the mound every day, whenever they call me to do my job. I’m happy to be here, so it’s out of my control.”