GLENDALE, Ariz. -- Kenley Jansen said cardiologist Dr. Koonlawee Nademanee "is the best probably in the world" and it must be true, because the surgeon not only fixed Jansen's heart but also his mind.
The Dodgers closer threw a bullpen session Wednesday as if he never had a 5 1/2-hour procedure performed in late November to correct a defect that caused an irregular heartbeat.
:: Spring Training coverage presented by Camping World ::
Jansen's early workout at Camelback Ranch was in marked contrast to last spring, when he coasted after a grueling 2017 campaign, suffered a hamstring injury rushing into shape just before the season started and struggled on and off right through the World Series.
Jansen said his heart is fine, mechanics are solid, velocity is not as important as late movement and he's hungry again -- not just because he's on a low-carb, low-sugar, non-dairy diet that helped him shed 25 pounds.
"He lost a sixth of himself," said Andrew Friedman, president of baseball operations. "He is extremely motivated. A lot of his struggles was the hamstring injury. Mechanically, he got out of whack. It was a good learned experience for him and bodes really well for this year."
Jansen agrees.
"Something in me is like, I got to prove everybody wrong," said Jansen. "I have the attitude since we lost the World Series, I just want to get better. Compete like I'm competing for a job, instead of having a vacation. We get to the finish line, but we don't go through the finish line, and that makes me more hungry. It's that mindset and I start now. My doctor told me to just go out and play and have fun.
"If you saw my bullpen today, I think the ball is coming out of my hand better than last spring. My arm slot is late still, that's normal, but the ball is coming out without trying, easy. Last year, I had a lot of problems with the [cutter] life. Got to be honest about it, I didn't have a Spring Training last year. Got the mindset, not just be a team leader, but the mindset of when you first get to the big leagues and win a job and be ready Day One."
That wasn't the case last year. His April ERA was 5.59 and that led to a bullpen in disarray. He rushed back from the irregular heartbeat episode in Colorado and struggled to a 7.88 ERA in August. He allowed two homers in four World Series innings.
"It took me a month after the hamstring to get back to myself and then my heart stopped me," he said. "I wasn't ready and I got hit with a lot of questions. This year, I know I'm going to have a Spring Training."
Jansen said he's not concerned that the weight loss means a velocity loss. It's more about movement and late life on the cutter, anyway.
"If you don't locate, it doesn't matter if you throw 105," he said. "I need the natural life at the end. Spin rate comes with life. I kind of started liking spin rate, it's better feedback than just velo. Velo can make you crazy, make you start bad habits. If you're 91, 92 or 93 and have a lot of swing-and-miss, you're doing OK. Greg Maddux didn't have velo at all -- shows you about location and movement."
Jansen said his spin rate Wednesday averaged 2,200. He considers anything above 2,000 acceptable and acknowledged there were games last year when his pitches registered 1,600-1,900.