"His type of competitive, winning attitude is contagious," said George Horton, Fullerton's associate head coach. "If you lined up the best 100 college players in America and asked me to pick one to play in just one game, I'd pick Kotsay. It's not just what he can do for you, it's what other players do when they're around him. He makes everyone else play up a level with his attitude."
It was the same way when he played at Santa Fe High in Santa Fe Springs as a quarterback and free safety in football, as well as an all-state baseball player.
Kotsay appears unaffected by his success. Even last Christmas Eve, he spent part of his day alone in the batting cage at Fullerton. It was typical of his unrelenting work ethic.
What he does this season will have financial impact, because he's eligible for the June draft.
None of last year's top seven choices received less than a $1-million signing bonus, with Erstad's $1.5 million from the Angels leading the way. The top 25 draft picks each signed for more than $500,000.
Kotsay is rated the seventh best pro prospect in Baseball America's preseason list. Five of the top seven, however, are pitchers, where scouts traditionally place heavy emphasis.
Kotsay, 6 feet and 180 pounds, has average speed by major league standards, and his throwing arm is hardly eye-opening.
There also is the question about how much his power will diminish when he starts using a wooden bat, rather than aluminum. But there is no doubt about what scouts call his "natural baseball instincts."
"He's the kind of player who constantly exceeds everyone's expectations," said Ken Compton, a special assignment scout for the Seattle Mariners. "Everything about him equals winner.
"He gets good angles to the ball defensively, and on the bases, he reads pitchers well, and knows when to take the extra base," Compton said. "He seems to have a tremendous grasp of what's happening on the field all the time."
Angel scout Rick Ingalls agrees.
"How many big, fast guys have you seen who didn't make it to the big leagues for one reason or another?" Ingalls said. "It takes something more, and I think Kotsay will make it. He'll find a way to play in the major leagues."
Kotsay says he only wants to continue taking things one step at a time.
"When I came to Fullerton, I just wanted to be the best I could be," he said. "And I still feel the same way."