Francisco Lindor exited Friday night's game against the Pirates with right side soreness. The star shortstop grounded out in the top of the fifth inning, wincing after he swung the bat and not fully running to first base in the Mets' 4-1 loss to Pittsburgh at PNC Park.

He was replaced by Luis Guillorme at short in the bottom of the inning.

Mets manager Luis Rojas said he knew something was wrong when Lindor was uncharacteristically slow to run out of the batter’s box during his at-bat. Rojas added that the extent of the injury was unknown after Friday’s game and Lindor will undergo tests on Saturday.

“It's tough,” Rojas said. "We've had a bunch [of injuries] already this season and this is a guy that works really hard [and] takes care of himself just to be out on the field playing every day. This is the one time where he gets the four days basically off and we're playing every day and then all of a sudden he has to come out of the game because of an injury. … The level of concern right now, it's obviously high just from not knowing. Let's just wait and find out more about it tomorrow.”

Lindor has had a down season by his standards, slashing .228/.326/.376 with 11 home runs. However, in the past two weeks entering Friday, he had put up a line of .314/.478/.486 with a 162 OPS+, so any missed games due to injury would come at an inconvenient time for both Lindor and the Mets, as they look to hold on to first place in the NL East.

If Lindor misses an extended period, the Mets have a few different options to replace him at shortstop.

New York could split time between Guillorme and Jonathan Villar at shortstop. Villar served as the club’s primary third baseman after J.D. Davis was placed on the IL in early May, but Davis was activated Friday night.

“You never want to lose anybody in your lineup, but especially a guy like Francisco Lindor,” said James McCann, who went 0-for-3 with a walk in the loss. “The way he's been swinging the bat lately, the way that he plays defense, that's a guy that you hope everything's OK and he's back out there soon.”

Against the Pirates, the Mets struggled to put together offense. New York scored its only run in the fourth inning after Villar grounded out, scoring Pete Alonso.

The Mets left opportunities on base in the early innings. Alonso and Jeff McNeil both reached base to lead off the second inning, but Pirates starter Chad Kuhl escaped unscathed.

Marcus Stroman, who gave up two runs in five innings on the mound -- and had an eventful night by exchanging barbs during a benches-clearing incident -- and Brandon Nimmo reached base with no outs to start the third inning, but Lindor grounded into a double play before Dominic Smith struck out to end the inning.

“It was a slow night,” McCann said. “We didn't come up with a big hit when we needed it. I had several opportunities. I didn't come up with a big hit. That's part of the game. That's why you play 162.”

The Mets finished the night leaving nine men on base and went 0-for-12 with runners in scoring position and have now lost three of their last five games to the Pirates, which included splitting a four-game series against Pittsburgh at Citi Field ahead of the All-Star break.

“It's frustrating to lose every game,” McCann said. “Any game that you lose is frustrating. I've never walked away from a loss and not been frustrated. It doesn't matter who your opponent is. Every day you show up, you show up to win and when you don't get a victory, it's frustrating.”