"He's pretty competitive," Rays manager Kevin Cash said. "Obviously, he takes a lot of pride in his defense, to be the best. And I think he's wanting to do the same thing from an offensive side. ... We all know K.K.'s a very special player, and as he continues to improve [offensively], he's going to become that much more special."
Kiermaier's fielding skills are well documented. He's created what he likes to call a "no-fly zone" in center field behind Rays pitchers. His fielding acumen is fueled by a combination of savvy, athleticism, aggressiveness and know-how. Kiermaier now hungers to make those skills translate more to the offensive side of the equation.
"I just want to be a complete player," Kiermaier said. "I appreciate what people say about my defense, but don't take away from my offensive ability. I know I can make a lot of noise up there, and I proved that last year when I came off the DL and I showed what kind of offensive player I can be.
"It's my goal: Just stay healthy this year, evaluate myself after, hopefully, a full season, and hopefully show everybody the type of player I can be over the course of a full season."
The Rays organization measures success in its run differential. Kiermaier already takes enough runs away. Now the possibility exists that he'll add to the differential from the offensive side.
Kiermaier hit a career-high 15 home runs in 2017, even though he lost 61 games to a stint on the disabled list with a right hip fracture. In addition, his 2017 batting average (.276) was 30 points higher than his '16 average. Much of that offensive improvement came in the 36 games after he returned from the DL, when he hit .306/.352/.517.
"I've had good offensive stretches throughout my career, but I've had some bad ones, too," Kiermaier said. "I want to find consistency, and I want people to know they'd better execute or I'm going to make them pay. And if I get on base, I'm going to be a headache for them.
"Hopefully, they'll throw the guy behind me some heaters and I'll be out there stealing some bases or taking the extra base. I also want to get down my bunts when the defense gives me that. I want the other team to hate me. I want to be that pesky-type player."
Kiermaier, already a decent offensive player, thinks he can become a great one.
"I think I can; I really do," Kiermaier said. "I need to go up there, swing at strikes. I have great hand-eye coordination. I'm a really good baseball player when I swing at strikes and I control the at-bats.
"When I start chasing, swinging at things I have no business swinging at, that's when things can go a little south for me. When I'm up there being selective and waiting for my pitch, I know I have the potential to be one of the best players in the game. I know that."
Bill Chastain has covered the Rays for MLB.com since 2005.