Is Justin Turner’s knee a growing concern for the Dodgers?

Justin Turner, the guy the Mets didn’t want, has become an almost indispensable part of this Dodgers team.

So much so that anyone who saw him grimace making that spinning stop of Wilmer Flores’ hot bouncer in the seventh inning has to be concerned.

Turner has been battling a bad knee pretty much the entire season and it was already flaring up in the series prior to that play. After landing on the infield dirt and then twisting around to make the throw that enabled Clayton Kershaw to complete his first clean postseason seventh inning in four starts, he batted in the top of the eighth and then left the game.

“He was a little sore yesterday during the game,” Manager Don Mattingly said. “He had some swelling. He was able to play, but as the game went on, he was going to have trouble moving.

“I expect J.T. to be able to play,” Mattingly added Wednesday in a conference call. “I don’t think there’s been a huge difference, a change from (Tuesday) in what he’s able to do.”

If the knee were to become so aggravated that he could not play, the Dodgers’ modest offense would be in trouble. Turner is batting .467 in the division series with four doubles.

Their backup third basemen are Corey Seager, Chase Utley and Enrique Hernandez. And they don’t really want to play Utley (a lifelong second baseman) or Hernandez (now starting in center) at third, where they have little experience.

Turner, a nonroster invitee a year ago who made the club as a utility player, is now one of the rocks in the middle of the lineup. The infielder the Mets let go two years ago is a player the Dodgers can’t afford to lose.

For now, he’s gutting it out and trying to keep it under as much control as he can. But at some point the Dodgers have to fear the knee will bark too loudly for Turner to keep going.