"He and I talk a lot, but I don't try to influence him," manager Joe Maddon said. "But he asks for advice a lot. We've had some really in-depth conversations.
"But a big part of his success is that he has his own methods. He sticks to it. We never press it with Tommy. We never ask, 'do you need more swings? What do you need?' He knows what he needs. Even on defense, he's gotten better."
Since joining the Cubs in a trade from the Braves prior to the 2015 season, La Stella has evolved from a power-challenged second baseman to an adequate backup at third (and second), as well as one of the top pinch-hitters in the league.
His 12 pinch hits (in 33 at-bats) lead the National League, and he's well within reach of the franchise record of 20 currently held by Thad Bosley (1995) and Dave Clark (1997).
Overall this season, he's batting .312 with a .384 on base percentage, through Monday's games.
And it was on-the-job training that helped La Stella master his hitting craft.
"I didn't really do much studying," La Stella recalled. "I just started from where I was. I didn't have much experience pinch-hitting, so it's just a matter of learning how to do it. It's just simplifying things, what I do well at the plate, and just doing that simply as I can over and over again."
"I don't get an opportunity to get four or five at-bats a game. There are plenty of times where I go into a massive stretch where the results don't match the process, but I can't be 'yard-saling' the whole plan over a few things."
La Stella attempts to keep a calm approach at the plate. "By the time I start the swing, I want to be in a decent position with my lower half and just to have my hands freed up.
"If I do that and don't swing out of the strike zone, I like my chances better than if I'm trying to dictate the pace on offense."
La Stella's methods rubbed off on rookie David Bote, who hit a pinch-hit, two-run double in the second inning that helped the Cubs rally to a 4-3 win over the Marlins on May 8.
"Tommy finds the perfect middle ground in preparing, but you wait until (your at-bat) is official," said Bote, now with Triple-A Iowa. "You're always ready and have a feel for the way is going. So if they say, 'Bote, you're going to hit if there are runners on base,' it wasn't a surprise."
As for his mentors, La Stella said, "I just take bits and see what works for me."
A 6-for-16 performance as a pinch-hitter in 2015 fortified La Stella's faith, which reached a crossroads when he was optioned before the trade deadline the following season. But he didn't report to Iowa, causing the Cubs to place him on the temporarily inactive list for 17 days and causing concern when the Cubs were focusing on their first World Series since 1908.
La Stella, 29, doesn't go into details of his absence, but mastering his role since his return has earned him respect.
"He's definitely evolved," Anthony Rizzo said. "You got a guy who goes great, and then 'quits' for his own personal reasons and then comes back. It's not easy to do. But he's been great."
La Stella also repaired his relationship with the front office, well enough so that he was comfortable exchanging pranks that including taking the spring training parking spots reserved for President Theo Epstein and general manager Jed Hoyer, and later setting up a bouncy house in the same location.
"This is a special place," La Stella said. "It truly is a much more of a family feel, and that's why we get so much out of the people who are around because everyone feels comfortable to go out and be the best version of themselves."
Maddon and Rizzo appreciate the fact that La Stella has worked to refine his skills while most of the attention is directed toward higher-profile teammates.
"It's not often anymore that you have a guy who sticks around with that kind of job in line," Maddon said. "Normally, that guy is moving along to another team by now. The fact that Theo and Jed and all of us have seen the value in it makes it a little bit different, too."
Said Rizzo: "I appreciate what he does because I can't do what he does."