The academy graduate had initially been named on the substitutes' bench for the game at Stamford Bridge on Friday night, with Axel Disasi and Levi Colwill occupying the full-back roles.
However, after Colwill aggravated a minor issue during the warm-up, Pochettino opted to hand just a second senior start to Gilchrist.
As well as Gilchrist coming into the team, it resulted in a reshuffle with Benoit Badiashile being used at left-back, rather than in a central role, and Disasi moving into the centre.
A goalless draw was eventually played out between the sides, which will lead to a replay at Villa Park likely on February 7.
After the game, Pochettino was naturally quizzed on the progress of Gilchrist, the 20-year-old having now made two starts and five substitute outings since making his debut on December 27.
The Argentine acknowledged that he felt the experience will be a beneficial one for his career, as well as the club's younger player in general at a time when several others have recently been handed their senior debuts.
Speaking to reporters, as quoted by football.london, Pochettino said: «Really good. It's one of the most difficult things to manage the stress because he knew he was not going to play and then he was going to play.
»Sometimes with the young guys, you give the starting XI and sometimes think too much and the stress can affect. But because it was 20 minutes or half an hour before the game, sometimes you think too much.
«All the young ones need time to be calm and relaxed and not spend so much energy thinking on the game. He was
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