From the outside, not too much has changed at this spot on Murphy Canyon Road.

The front of the building still reads “San Diego Chargers,” as it has for two decades. The back still displays billboards for division championships, still shows off a balcony with lightning bolt-styled railings. And, for a few more days, the fields will still be overrun by NFL players.

The Chargers are set to hold a mandatory minicamp Tuesday through Thursday, the last set of NFL practices San Diego will see in the foreseeable future. Practically speaking, these sessions won’t look very different from the team’s recent OTAs, free from contact and full pads. Emotionally, this will represent — for some veterans — a final goodbye.

Take, for example, Philip Rivers, the 35-year-old quarterback who has not missed a start for the Chargers in over a decade. In April, he was asked how he felt about his team’s impending move — one that had been announced in January, but nevertheless left the players in geographic limbo. Relocating next month to the team’s new facility in Costa Mesa, he responded, wouldn’t quite hit him until he stepped out of Chargers Park for the last time.

“This is where I’ve spent more hours — next to my house, it’s been right here,” Rivers said of the team’s headquarters three miles north of Qualcomm Stadium.

Most of his teammates don’t share those deep roots. Only eight players on the Chargers’ roster have turned 30 years old.

Among those still in or entering their primes is 28-year-old Melvin Ingram, the franchise-tagged edge rusher who on Sunday agreed to a new four-year deal — saving the Chargers from a summer of contractual drama. Absent from the bulk of the offseason program while negotiating a new contract, Ingram will enter minicamp with something to prove: That he can transition seamlessly from outside linebacker to defensive end.

Limited by injuries in his first three seasons, the former first-round pick out of South Carolina broke out in 2015, notching 10.5 sacks in the 3-4 system run by then-defensive coordinator John Pagano. Last season, Ingram paired with rookie sensation Joey Bosa to form one of the most talented pass-rushing duos in the league.

That type of talent is a coach’s dream. The next step is tailoring it to the right scheme.

The Chargers gave up 423 points last season, fourth-worst in the NFL and the most they had allowed in over a decade. But that number was inflated by their league-high 35 turnovers. By several other measures — including yards per game and opponent third-down percentage — the defense ranked in the middle of the pack.

The franchise didn’t draft a defensive player until the fourth round, so any immediate improvement will likely depend on improved health and internal development. New Chargers defensive coordinator Gus Bradley — still best known for his work in Seattle — is instituting a 4-3 system, albeit one that he said will incorporate some 3-4 elements. For Ingram, that will mean moving closer to the line of scrimmage, though given the same general assignment: Get to the quarterback.

Helping Ingram’s transition is Bradley’s philosophy, which emphasizes speed and fundamentals over a complicated set of calls. Although a heavier hand could introduce more chaos into the offensive backfield, he said, it could also risk overloading playbooks and making players a step slower.

“The advantage of this style of defense,” Bradley said earlier this year, “is it allows guys to come in and play right away.”