Mets fans didn’t care it was a line drive off Carlos Beltran’s bat. Didn’t care it was scorched.

When Beltran lined into a double play to right field because Miguel Cairo was caught off first base in the eighth inning Tuesday night, the boos cascaded down from Shea Stadium.

Two innings later, the Mets center fielder finished an 0-for-6 game with another double play, this time a more traditional 3-6-3 twin-killing.

“That’s the way they react,” Beltran said. “When I hit that ball to the right fielder, I got frustrated.

“I hit it as hard as I could. Like I say, I can’t control the fans. The only thing I can control is the way I play the game, that’s it.”

Following the Mets’ 9-8, 11-inning victory over the Brewers late Tuesday, Beltran sounded defiant when he said, “What do you want me to do? If they want to continue to boo, they can do it.

“I’ll be here for seven years.”

Beltran is no shrinking violet, and it sounds as if he can handle the abuse. But the fans aren’t going to go easy on him in the final 55 games of this season, and his mediocre performance after signing a seven-year, $119 million contract is contrasted with Pedro Martinez’s Cy Young Award-contending effort.

Entering last night, Beltran was batting .263 with 12 homers and 56 RBIs. Willie Randolph keeps repeating that his center fielder will be fine and that he’s going to end up having a good year, but what kind of finish does the manager really expect?

“You remember watching the playoffs last year, when he was real hot?” Randolph said somewhat sarcastically. “I’d like to see that. That would be nice.”

Through the first 106 games (not including last night), Beltran hadn’t done that. In early June, Houston manager Phil Garner said Beltran’s production at that time might be all you get from him.

For much of the first half, a strained right quad bothered Beltran, but now he doesn’t have the answers.

“I come to the ballpark every single day to work,” he said. “I feel good; in the cage I do real good work. When the game starts, it seems like nothing goes my way . . .

“I’m not worried about me. When it’s going to change, I don’t know. But I feel like it has to. It can’t stay like that for the rest of the season.”

Mike Cameron went through much of the same adjustment periods, first when he was traded to Seattle for Ken Griffey Jr., and later when he signed with the Mets.

“I don’t think he truly had to go through an experience like this before,” Cameron said of Beltran. “It’s all gonna pass over.

“The good thing is, no matter how things are, we pull for him. That’s the reason Willie keeps sticking him in the three-hole [in the lineup].

“Everybody goes through it. As long as you work hard and try to do things right, there’s nothing else you can do. If people see different, so be it.”

As of yesterday, the Mets needed to outplay five teams to win the NL wild card and were 7½ games behind the first-place Braves in the NL East.

Randolph was asked, point blank, if his team could reach the playoffs based on Beltran’s current production from the No. 3 spot.

“We can do it; it’s possible,” Randolph answered. “It would obviously make it a lot easier if he gets on one of those hot streaks.

“That’s the thing: It’s not about Carlos; everybody needs to step up . . . Of all the guys on the team, I don’t worry about Carlos Beltran.”