It’s nitpicking, but Matt Harvey has room for improvement on what has been a spectacular body of work to start the season, according to catcher John Buck.

When the Mets’ phenom takes his 4-0 record and 0.93 ERA to the mound against the Dodgers tonight, Buck wants Harvey to reduce the number of overthrown pitches he unleashes. Buck says Harvey has averaged about 10 overthrown pitches in his first four starts.

“Every once in a while he’ll overthrow his fastball or he’ll yank his slider too much or he throws too hard where he backs it up,” Buck said yesterday. “It’s still nasty, but sometimes he will overthrow it and not get the break that’s the real nasty stuff.”

By executing better on just a few pitches per game, Buck said it could allow Harvey to extend his starts by an extra inning, because hitters will presumably be putting the ball in play earlier in the count.

Buck says he has already had that discussion with the 24-year-old fireballer.

“Even though he’s pitched real well, he’s thirsty to get better,” Buck said.

In his last start, Harvey allowed one run over seven innings to top Nationals ace Stephen Strasburg.