NEW YORK — The New York Mets have recalled right-handed reliever Seth Lugo from Triple-A Las Vegas.

The Mets made the move before Friday night's game against San Diego.

Earlier in the day, Mets manager Terry Collins said lefty Jon Niese "has got a little bit of a knee issue."

"We wanted to protect our pitching, so Lugo's here," he said.

Outfielder Michael Conforto was optioned to Triple-A. After a successful rookie campaign last year, he has hit just .218 with New York this year.

"I think he's pressing. I think he's starting to expand the zone too much," Collins said.

The Mets also said right-hander Zack Wheeler, who began a rehabilitation assignment with Class A St. Lucie on Saturday, is scheduled to see noted orthopedist Dr. James Andrews. Wheeler complained of elbow discomfort following a recent rain-shortened start in which he threw 17 pitches over one inning.

Lugo made his major league debut on July 1. This is his third stint with the Mets.