The Reds vs the Blues has become one of the division’s fiercest rivalries over the last 15 years, with both sets of fans establishing a mutual enmity during Rafael Benitez and Jose Mourinho’s hotly disputed clashes in the mid-2000s.
The sides then were almost annual opponents in the Champions League. In fact, from 2004-05 to 2008-09 the clubs were paired together in Europe for five seasons in a row.
They also contested some stellar matches in the FA and League Cups and, of course, in the Premier League during that time.
The rivalry has not dampened down over the years, not least given the infamous game in 2014 when Steven Gerrard slipped against Chelsea to allow Demba Ba to score.
Five years on, Firmino is hoping Liverpool can avoid a calamitous defeat against the London club, but is expecting an equally competitive affair at Anfield on Sunday.
“It should be a good game - they are a great team, with great players, we know that," the Brazilian told Sky Sports.
"It's a classic, a great game, and we will have to be 100 per cent switched on, focused on the game, and do our best - that is the most important thing
“Chelsea are a great team, they had an excellent start to the season, but unfortunately couldn't continue that run of results and fell away a little.
“But they are still fighting for a top-four spot, Chelsea are a great team, regardless of who they may have lost to recently. So it's going to be a great game, and I hope we are alert and can win the game.”
The Reds ensured they stayed at the league’s summit last time after overcoming Southampton 3-1. The game turned on Mohamed Salah’s late strike and Firmino knows he could prove to be the difference again on Sunday, against his former side.
"It was a really decisive goal, a comeback goal, and then we obviously went on to score the third,” said Liverpool’s No.9. “It's very important for him to take confidence from that in the league and the Champions League.
“It's also very important that he's scoring and helping us win games," he added. "It was really important for him to get back to scoring because it had been a while since he scored.”
Firmino himself is enjoying a superb campaign for Jurgen Klopp’s side and has provided 12 goals and seven assists in the league.
“In my view, I am good, I'm 100 per cent and I feel great,” said the 27-year-old.
"I've got a lot of belief, and I just want to help my team-mates win games, giving my all out on the field. I hope we can do our best, achieve our goals, and that I can continue helping my team.