The 22-year-old Belgian will surpass his previous best stretch of 518 minutes without injury, pre-season included, if he completes 60 minutes against Brentford on Friday.
It is a striking turnaround for a player who made only one appearance in his debut season at Stamford Bridge because of a serious hamstring injury, then missed 33 matches the following campaign, before improving his availability last term by featuring in roughly half of Chelsea's games.
"There is so much that goes on behind the scenes," Lavia told BBC Sport, revealing he follows a personal checklist to make sure he is in the best possible condition for every match. "It's a big process but we're doing well at the moment."
The Belgian credits both a mentality shift and the support of those around him for helping him push through repeated setbacks without becoming overly cautious — something head coach Xabi Alonso challenged him to overcome during a pre-season match against AC Milan in August.
"I've learned you can always go further than you think you can. You can always push your limits, especially when you feel like everything is going against you," Lavia said.
"It's always easy to think about giving up, or to feel that whatever you do will take you back to the same point where you started. But luckily, with the help of team-mates, staff, everyone at the club and people close to me outside football, we've been able to create a sort of bubble where you concentrate only on what you can control."
With Reece James and Wesley Fofana having overcome similar fitness struggles, Lavia has become a fixture alongside captain James in Alonso's midfield, his role heightened by Moisés Caicedo's limited game time this season and Enzo Fernández's £125 million deadline-day move to Manchester City.
"It's part of my game as well to take responsibility and have some character," Lavia said. "I really like being in that position and also being at this club. Having this responsibility, it's not even pressure, it's just like privilege, so I'm actually living the dream."
Chelsea's attacking form has fed Lavia's own sense of freedom, with the club scoring 18 goals in six matches this season, aided by £117 million club-record signing Morgan Rogers from Aston Villa.
"It's honestly amazing," Lavia said of the front line he now plays behind. "Obviously I knew Morgan, but just the way he's come in and then they've all clicked together up front. Sometimes I wish I could go in the stands and enjoy watching it."
Lavia's breakthrough moment came with his first Chelsea goal, in a 4-3 win over Brighton — a fixture with added meaning, since his first Premier League goal of any kind came against Chelsea while at Southampton in 2022.
"It was just a moment where I felt free," he said. "It feels like all the work that you're putting in, you gain the reward of it, so it was a very emotional moment. I wanted to change the narrative."