New York Mets Matt Reynolds (56) during warmups before the...

New York Mets Matt Reynolds (56) during warmups before the Mets face Dodgers at Citi Field in Queens during Game 3 of the NLDS on Monday, Oct. 12, 2015. Credit: Jim McIsaac

PORT ST. LUCIE, Fla. — With Asdrubal Cabrera unlikely to be ready for Opening Day because of a knee injury, shortstop prospect Matt Reynolds has a chance to make his major-league debut when the season opens on April 3.

Reynolds has never spent a regular-season day in the majors. But he was on the Mets’ roster for Games 3-5 of the NLDS against the Dodgers and the Mets’ NLCS sweep of the Cubs after Chase Utley broke Ruben Tejada’s leg.

Reynolds didn’t get into any postseason games and was replaced on the World Series roster by Juan Uribe, who returned from a chest injury.

Still, Reynolds had the ride of his life for a round and a half while watching from the bench.

“It was so much fun,” said Reynolds, who went 0-for-2 and misplayed a ninth-inning grounder (it was scored a single) in the Mets’ 14-9 loss to the Cardinals on Saturday. “I expected one thing and it completely blew it out of the water. It was unbelievable.”

Reynolds, who returned Saturday after missing four days with a strained right hamstring, was a heartbeat away from pinch running in Game 4 of the NLDS and pinch hitting in Game 1 of the NLCS against Jon Lester of the Cubs.

“There was a couple times,” Reynolds said. “There was an opportunity that I was going to get in and pinch hit against Lester. I forget what game it was, but we were down in the ninth, and if someone got on, I was going to pinch run for them. But it didn’t work out. Oh, well. I was there just to help the team win, and if I went in, that was great. If I didn’t, that was fine.”

If he had gotten into a game, Reynolds would have become the first player to make his big-league debut in the postseason since Oakland infielder Mark Kiger played in two games in the 2006 ALCS without an at-bat.

Kiger never played in a regular-season game. Reynolds, 25, is a good enough prospect that his fate should be different.

“That would be nice to get an AB, for sure,” Reynolds said.

His chances increased when Cabrera suffered a strained patella tendon while running the bases on Thursday. Cabrera will be inactive for at least two weeks.

“It’s terrible to have Asdrubal go down like that, but someone’s got to step up and take that spot,” Reynolds said. “I’m just happy that I have the opportunity to go out there and compete.”

Wilmer Flores made his first appearance at shortstop of spring training on Saturday and went 0-for-1 with a walk before being replaced by Reynolds.

The Mets had Flores pegged to be a jack-of-all-infield trades and the primary backup to David Wright at third. Wright will make his first appearance of spring training on Monday in a minor-league game as the Mets are bring him along slowly because of his spinal stenosis.

Ruben Tejada also is in the mix at short, though the Mets had been considering trading him before the end of spring training to shed his $3-million salary. The Cardinals, who lost Jhonny Peralta until midseason with a torn thumb ligament, are looking for a replacement.