Kansas City, Mo. ? Former Kansas University baseball player Rob Thomson, working in the New York Yankees organization since 1990, has had a close look for most of that time at the career of future Hall of Fame shortstop Derek Jeter.

The difference, in terms of mental approach to the game, between the teenager who committed 56 errors in the Class A South Atlantic League in 1993 to the star who won so many pennant-race games with ninth-inning hits to the man who flied out to right for the final out of Sunday’s 1-0 loss to the Kansas City Royals?

“It’s amazing how time flies, but this guy is the same guy he was as an 18-year-old,” said Thomson, third-base coach for the Yankees. “Very respectful, hard worker and very professional. I don’t see any change in him since he was a kid as far as his enthusiasm and his work ethic.”

Jeter’s 0-for-4 against Royals right-handers Bryan Bullington (eight, two-hit innings) and Joakim Soria (33rd save) Sunday dropped his batting average to an atypical .279. Jeter’s numbers are down, yet his head remains up on his way to another deep October.

“He never gets down,” Thomson said. “You never know when he’s in a slump or when he’s struggling. He’s an even-keeled guy, and he’s a very positive thinker. He always knows he’s going to do well, even when he’s not doing well.”

Thomson spent much of the 1993 season in Greensboro, when Jeter made all those miscues.

“He made 56 errors that season, but he made 40 of them in the first half,” Thomson said. “That was impressive how much better he got during that year.”

Watching Jeter blossom into a superstar has been just one of the many professional thrills for Thomson, taken in the 32d round in 1985 by the Detroit Tigers, who after 21/2 years of employing him as a player, asked him to become an instructor. Since joining the Yankees, Thomson has been a minor-league coach and manager, farm-system director, spring training coordinator and for the past three seasons a big-league coach.

During that time, he earned the respect of the late Yankees owner George M. Steinbrenner III. The feeling was mutual.

“He was a great man,” Thomson said. “He cared about winning. He cared about the organization. He cared about carrying on the tradition, and he really cared about his players.”

When Thomson gets his shot as a big-league manager — and he will — don’t look for him to be one of those guys who tries to cultivate the genius label. He knows what all great managers have in common.

“It’s about players,” Thomson said. “That’s why people come to the ballpark and pay their money, to see these players play. So if you give them every avenue to be at their best, you’re doing the right thing. That’s what Mr. Steinbrenner did.”

Yankees manager Joe Girardi weighed in on how he thinks Thomson will handle his first shot at managing

“Because of his understanding of the game, the way things should be done and his rapport with the players, I think he’d be great,” Girardi said.

Sharing with players how Jeter handled failure to stay on a path to success can only help Thomson as a manager.