Nuñez is still a work in progress

Late in a May 4 night game in Detroit, Derek Jeter's right hip stiffened up. In the series finale the next afternoon, Joe Girardi started Eduardo Nuñez at shortstop in Jeter's place.

The day started well enough for Nuñez, who had played sporadically to that point. He bunted for a single in the third inning and lashed a run-scoring single to right in the fourth.

But in the bottom of the same inning, after cleanly fielding Brennan Boesch's grounder, Nuñez threw low to Mark Teixeira at first for an error. In the seventh, he again threw wildly after fielding Don Kelly's routine grounder, leading to two unearned runs in a 6-3 loss.

"That's supposed to be Jeter's replacement?" an opposing team's scout said the next day. "Not good."

But the scout wasn't dismissing Nuñez -- "the kid makes a lot of solid contact at the plate," he said -- and brought up an issue that first-base coach Mick Kelleher, who also instructs the infielders, had noticed: Nuñez, 24, seemed to overcomplicate things in the field. An infielder, like a slumping hitter, can have too many moving parts.

"We just worked on rhythm," Kelleher said recently. "Catch the ball and release the ball. You catch the ball, you set up, bam. And you don't have to throw it hard because you're getting rid of the ball quickly . . . It's kind of cleaning up unnecessary things."

Before a game June 18 in Chicago, Girardi noted the improvement that Nuñez -- who has battled a tendency to drop his arm angle on throws instead of coming over the top -- had made in the field since Jeter went on the disabled list June 14.

The way these things go, of course, Nuñez made two throws later that day that required some good work by Teixeira to record the outs. Nuñez also was charged with an error on a bad-hop grounder in the sixth.

The error was Nuñez's second since replacing Jeter. He has a team-high 10, including four since replacing Jeter, who had four errors in 62 games.

Current Trenton Thunder manager Tony Franklin, who managed Nuñez at Double-A Trenton in 2009, said Nuñez -- who was signed as a non-drafted free agent in 2004 -- initially had some tough times in the field.

"He faced some issues of consistencies, the same areas he needs to shore up now," Franklin said this week. "But he made strides in those areas."

Nuñez hit .322 that season for Trenton, demonstrating what several scouts have touted as the shortstop's best attribute since he took over for Jeter.

The fielding remains a work in progress, but Nuñez seems to make solid contact just about every at-bat. "This guy's a hitter," Franklin said. "He can take a bat and put it on a ball as well as anyone I've seen."

But after a hot start at the plate after replacing Jeter, Nuñez has slumped. He went 0-for-4 Thursday against the Brewers, falling to 13-for-51 (.255) since June 14, and is in a 6-for-33 slide. Still, he's hitting the ball hard and has struck out only four times in that stretch.

"We've always thought he's an everyday shortstop in the big leagues," said general manager Brian Cashman, who has refused to part with Nuñez, including last summer, when the Mariners wanted him as part of one proposed deal for Cliff Lee.

Kelleher, a roving infield instructor in the organization from 2006-08 before becoming the first-base coach in 2009, said Nuñez's arm is as good as he's seen.

"He's got a very, very strong arm; he just has to keep it under control," Kelleher said. "People with good arms, great arms, they want to show it off . . . The whole thing is coming together. And what is he, 24? So, man, he's an exciting young player to watch play. We haven't seen the best by any means yet."