On this day in 1998, John Terry made his Chelsea first-team debut in a 4-1 victory over Aston Villa.

Eighteen years later, the club legend languishes in footballing limbo, uncertain of his role in a squad where his name was once the first on team sheets. He needn’t worry.

Terry, who turns 36 in December, appeared rusty in Chelsea’s midweek League Cup defeat to West Ham after returning from a six-week injury-related absence.

That’s not to say that the 78-time capped former England international is of no value to the club. On the contrary – especially with central defender Kurt Zouma still recovering from a broken leg – Terry’s presence is of great importance to Antonio Conte’s squad.

Few know that better than the gaffer.

“John is an important player for us. If he plays or if he doesn’t play, in the changing room and for the teammates and for the club,” the Italian gaffer told the Daily Mail’s Matt Barlow ahead of Sunday’s south coast sojourn to face Southampton.

“It is logical John came back from injury and it’s not easy to find quickly the right shape,” Conte said on the topic of Terry’s match fitness.

At the London Stadium Wednesday, Conte opted again for the 3-4-3 formation, with Terry to the left of Gary Cahill in a central position and David Luiz on the right.

The former Italy manager first used the formation during the second half of a 3-0 defeat to rival Arsenal when he introduced summer signing Marco Alonso in the second half as a wing-back. Since then, the tactics have served Chelsea well, and with Zouma’s time frame uncertain, Matt Miazga on loan with sister club Vitesse, and Branislav Ivanovic being a shadow of his former self, Terry could play a vital role for Chelsea.

Pair that with the mercurial performances of Cahill and Luiz’s affinity for daft decisions, and Terry’s aplomb in the penalty area is still of influence for a side desperate to better last season’s drab 10th-place finish.

“It’s not a win or a defeat that can change my idea or the confidence of the players. After Arsenal and Liverpool defeats, in the future we never must play with 4-2-3-1. It’s not only the problem of the system,” Conte added.

If there was any doubt that Terry is slated to play a role in Chelsea’s pursuit of a fifth Premier League title in 13 years, Conte’s insistence on employing his formation of choice should dispel those hesitations.

“It’s the right way for the players. It’s a good fit for the team. We found a good balance and also we have a good offensive situation because in every game we score a goal.”

A decorated career has seen Terry win 16 trophies with Chelsea, and he may very well add to that collection in what is likely to be his final campaign with the club.