The Mets have the best scout in the world when it comes to evaluating Cuban free-agent third baseman Yulieski Gourriel.

That scout batted third for them Wednesday night at Citi Field in the Mets’ 11-2 blowout of the Pirates.

While playing in Cuba, Yoenis Cespedes was teammates and close friends with Gourriel, and told The Post that Gourriel can have a tremendous immediate impact in the major leagues.

“At the time that I left that was the best ballplayer in Cuba,” Cespedes said through interpreter Melissa Rodriguez. “He is a five-tool player. When I was in Cuba we were best friends.”

The Mets need to make a serious run at the free agent. With David Wright likely heading to neck surgery, the Mets desperately need to find a solution to their third-base problem and think about putting together an offense that takes full advantage of the super pitching staff.

Don’t let one night of big offense against Jeff Locke (5.92 ERA) fool you, the Mets cannot afford to continue to struggle offensively and waste superior pitching.

I asked Cespedes where he thinks Gourriel, 32, will wind up. Cespedes smiled and said, “All I know is that when I heard [Hector] Olivera was getting $62 million, my first thought was Yulieski is worth way more than that. I don’t know what team is going to pay what he is worth.”

Olivera was a bust with the Dodgers, was traded to the Braves and is currently suspended for violating MLB’s domestic abuse policy.

As we were talking, Cespedes leafed through a set of baseball cards featuring Cuban stars and picked out Gourriel’s card as he described the talented player.

If Cespedes says Gourriel can play, you can be sure he can play at the major league level.

The Post’s George A. King III reported Wednesday the Yankees have shown an interest in Gourriel, according to several industry members involved in the international market, and Aroldis Chapman, who was teammates with Gourriel on the Cuban national team in the World Baseball Classic in 2006, said he has all the qualities to be a good player at the major league level.

Cespedes was on Cuba’s 2009 WBC team with Gourriel. In the past, the Mets have not gotten involved in the free-agent market for Cuban players but that needs to change, especially if the Mets lose Wright to surgery.

Gourriel also can play second.

Juan Lagares was scratched from Wednesday night’s lineup because of his thumb injury. Neil Walker was out again because of his back injury and got an MRI exam. Lucas Duda is out with a bad back. Travis d’Arnaud (shoulder) is not returning until next week. Michael Conforto has a sore wrist.

“This is a team with a lot of holes,” said one scout at the game Wednesday night.

Replacing Daniel Murphy with Walker was not the problem; not understanding the flexibility Murphy offered was the problem. There were some in the organization who wanted Murphy to become the everyday first baseman, certainly he could have provided Wright insurance at third base.

Murphy leads the majors with a .359 average. The Mets, meanwhile, went into Wednesday’s game 28th in runs (229) and batting average (.231).

The Mets started Wilmer Flores at third again Wednesday night and he hit his second home run of the season. Terry Collins shifted utility man Kelly Johnson (who also homered) to left, while putting Cespedes in center. Cespedes (three hits) lined the ball so hard in the fifth that his bottle-rocket to left bounced and hit Starling Marte in the face, knocking Marte out of the game.

Cespedes knows talent, and any team that lands Gourriel is immediately improved.

Noah Syndergaard was magnificent again with 11 strikeouts. The pitching will be there for the Mets. It’s the offense that is the concern.

It’s expected Gourriel would be in the majors about a month after signing. The Mets have to look for different ways to solve their problems and this is something that only costs money.

Of course, getting the Mets to spend big money always is an issue.