Buster Olney is on vacation this week, and some folks with baseball ties have been filling in as guest columnists. Today: Los Angeles Dodgers starter Brandon McCarthy, who joined the Dodgers during the offseason as a free agent and is working his way back from Tommy John surgery.

“I’ll tell you what, if I throw like that this year, Kersh better watch out.” -- Zack Greinke during spring training

At the time, after Zack had just breezed through a lineup of minor leaguers in a game on a back field, it sounded like typical overly positive pitcher-speak that only occurs in spring training before the ability of major league hitters is remembered.

Clayton Kershaw, the winner of three of the last four NL Cy Youngs and the reigning NL MVP, is not someone who has to “watch out” for anyone. He’s seemingly competing only against the all-time greats and the limits of our imaginations. Everyone knows that Zack is a superstar, but conventional wisdom says that Clayton is living in a different solar system.

Five months later, Zack has actually been every bit as good as Clayton -- and it’s clear that Zack's spring training statement wasn’t tossed out haphazardly. In fact, he meant every word of it. He knows exactly where his stuff needs to be for him to be at his best, and he felt that everything had clicked.

Zack's statement helped me and his other new teammates realize exactly what kind of guy he is. Small talk doesn’t interest him and he chooses his words very carefully. He doesn’t say anything he doesn’t mean. He’s not overly positive or cocky. Rather, he’s very down to earth, and fully self-aware -- and he is as quick to critique himself as he is to realize when he’s executed something to perfection. Those who don’t take the time to get to know him miss just how much he brings to the table when he talks. He’s realistic, measured and unflinchingly honest.

While Clayton and Zack now typically arrive at the same dominant results after their games, the way they get there couldn’t be more different.

"Small talk doesn't interest Zack, and he chooses his words very carefully. He doesn't say anything he doesn't mean. He's not overly positive or cocky. Rather, he's very down to earth, and fully self-aware -- and as quick to critique himself as he is to realize when he's executed something to perfection." Dodgers pitcher Brandon McCarthy on teammate Zack Greinke

Kershaw is an extreme perfectionist. He’s fanatical about his routine. It’s set in stone, and everything that needs to be done to prepare for his next start will be done on time with maximal effort. Once he’s at the field, there is no one easier to find than Clayton. You don’t have to see him to know exactly where he is at any given time, you just have to know his routine.

Finding Greinke, however, is like trying to find the wind. He’s found only when he makes himself discoverable. He describes his routine as being based on feel. Some days that means he needs to do eight sets of squats. Other days it means using a foam roller for an hour in a far corner of the weight room while reading a magazine. He disappears for hours at a time. He wanders around carrying a plate of food as if he’s at an outdoor cocktail party. He’ll watch video when a certain player happens to be on his mind. A “routine" like this is usually a major red flag about a player. The best players in the game typically are known to live and die by their routines, but nobody knows what Zack needs better than Zack, so his anti-routine is never called into question.

Their differences extend to their pre-pitch habits, as well. Kershaw works quickly and has the mound composure of a bully. It looks like he cannot wait to deliver whatever unhittable pitch he’s decided to throw, and when that’s done, he wants the ball back as soon as possible so he can do it again. He overwhelms hitters with three pitches that work together perfectly, and he delivers them with supreme confidence.

Zack moves much slower on the mound. He bounces the ball off his glove while he composes himself and thinks about what he wants to use from his toy box of pitches. It gives the impression that he’s allowing the hitter a moment to enjoy some time in the box before he’s sent back to the dugout. He pitches like he speaks. Carefully, methodically and full of confidence.

Once a pitch is released, however, the two are as similar as can be. Both have impeccable command and the ability to fool the best hitters in the world. The ease of their games gives off the feeling that we're watching something scripted. Hits -- and especially runs -- against them seem to deserve applause from both teams because of their rarity. Both Zack and Clayton take immense pride in their fielding, hitting and baserunning. They do everything possible to help the team win until they’re removed from the game. The moment it counts is when it’s hard to tell the two apart.

Major leaguers are always curious about their peers. We want to know what other players are like behind the scenes. Hard worker? Nice guy/good teammate? Does he do anything weird? We ask these questions to anyone who will answer, but it’s hard to get the whole story until you’re in the same clubhouse.

As someone who’s been in a dugout across from the Dodgers for the last few seasons, Zack and Clayton were the two guys I wanted to know about the most. Now, as their teammate, I’ve had my questions answered, and both have been as good as I’d hoped.

Players want to know that the best truly care about their craft and work diligently at it. We hope to find out that the players we admire from across the field have all the qualities that we project upon them, the same way fans outside the game might. Hard workers, good teammates and good people are respected throughout the game, and you never want to find out that you’ve been fooled by good statistics.

Yes, Zack is as smart as we all think he is. Yes, Clayton works as hard as anyone in the game. Both are good people and teammates, and you can count on them. I’m lucky to be behind the scenes to see how they conduct themselves on a daily basis, but anyone watching them on TV is already seeing just who Clayton and Zack are.