"It has been real comfortable starting from day one when [manager] Ron Washington called me into his office. Everything has been great.
"We had a meeting in Spring Training and Wash said to me, 'You are a clown.' So basically, be yourself, have fun and play hard. From that point on, I knew I could be myself."
Doing exactly that has allowed Napoli to have a career year.
Going into Wednesday's regular-season finale against the Angels, Napoli had already belted 28 home runs to go along with 72 RBIs, both career highs. He's also racked up a career-high 116 hits, 70 runs and 25 doubles.
"He has done a great job and stayed healthy and been very productive," Washington said. "He's also been a great teammate and we are very happy to have him.
"He's been consistently swinging the bat. He has always had the power."
One thing that also bounces off the stat sheet is Napoli's average this season.
He entered Wednesday hitting .317. The highest average Napoli ever had in his five seasons with the Angels was .273 in 2008.
"Mike has the potential to be a higher average hitter than maybe he has shown at times and has really put it together this year," Angels manager Mike Scioscia said.
Getting protection in a lineup that includes such sluggers as Josh Hamilton, Michael Young, Ian Kinsler and Adrian Beltre, Napoli also said his approach at the plate has improved this season.
"My two-strike approach has been a lot better," Napoli said. "I worked hard this year to try to go out and give the best at-bat I have and get deep into counts."
But it's not just offensive numbers. Napoli has had a standout year defensively.
In 56 starts behind the plate, Napoli came into Wednesday's game with a 3.19 catcher's ERA, the best mark in the American League and third best in the Majors with a minimum of 50 games caught.
Texas has also gone 41-15 in his starts behind the plate, including 10 straight wins.
"He is like a brick wall back there," Rangers starter Derek Holland said. "We call him 'Full Grown.' He has a lot of character and knows what he is doing back there.
"He's been a key part to why I have done so well this second half. He's caught a lot more of my games now. The chemistry we have with each other helps out."
Napoli doesn't get caught up in the defensive numbers he's accomplished this season. Instead, he's focused on winning games.
"For me, it is all about catching a winner. If we give up seven runs and we scored eight, what do I care," Napoli said. "I take pride in catching well though. I work hard at it and things are working out."
With Napoli also starting 27 games at first and 18 at designated hitter, Washington believes he has found a winning combination to keep Napoli productive and healthy.
"It has benefited him a heck of a lot," Washington said. "He hasn't had to do all of that squatting all the time. He gets the chance to DH and play first and has found his stroke."
Napoli will try to keep such a pace going in the playoffs, where he will play a pivotal role for the Rangers as an everyday player.
"In some way shape or form he'll be out there every game," Washington said. "We need his bat in there. We need his presence."
Quinn Roberts is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.