Elliott came off the bench in the second-half as Liverpool won thanks to two injury-time goals from Darwin Nunez.
Slot said afterwards: "I was (delighted by his performance when he came on) and I'm happy we give you a chance to ask another question! All the other interviews, there was a lot of focus on Darwin because he scored two goals and every time I said, 'Yeah, but don't forget Harvey – he had a big impact on both goals as well.'
"It's so nice for me, for us as a team, that I have players that can impact the game on the bench as well. This happened at Forest with (Diogo) Jota and Kostas (Tsimikas) and today with Harvey and with Darwin.
"If you only focus on results again, if you also focus on performance – which I do – I also liked Robbo and Curtis (Jones) when they came in and Federico (Chiesa) was only (on) for five minutes, so you can't say a lot about that. But it's nice to have so many opportunities on the bench, that's why they have to stay available, they have to stay fit, because one of the strengths of the team is not only four good centre-backs but definitely also players that can impact the game from the bench."