The goal was his fifth in all competitions and just his third in the Premier League this season, but the German is delighted with what he has produced from a deeper role.
Per Goal's Dejan Kalinic, he said:
"Because of the small things he's doing, he's working so hard, he's here, he's there, he's got five goals but he opens 5,000 gaps for everybody.
"It's about how you see it. He will never come to me and say, 'Because people are writing something is missing, could I play my old position again?'
"He's doing the job—that makes him so unbelievably valuable for us. I'm really happy for him. It's just about what we have to do in the right moment—we have to find a system where we can bring our quality on the pitch, and on Saturday we did it."
Sports journalist Jack Sear relayed further comments Klopp made on Firmino to Ian Doyle of the Liverpool Echo:
At Vicarage Road, Firmino added the finishing touch for the Reds after Mohamed Salahand Trent Alexander-Arnold had fired them into a two-goal lead.
The Brazilian's 89th-minute goal put the game to bed after Jordan Henderson had created a slightly tense end to the match after being sent off seven minutes prior.
Firmino's close-range header capped a strong all-round performance as he tucked in behind Salah, who spearheaded the attack rather than occupying the right wing.
Squawka Football shared his numbers:
The 27-year-old enjoyed a sensational campaign last season as he racked up 27 goals in all competitions.
However, it's not surprising he hasn't been as prolific this time around. Last season was only the second time in his career that he had surpassed 12 goals, having netted 22 times in his best campaign with Hoffenheim.
While last season he produced some exceptional numbers, he has reverted to type again.
Unlike some forwards, Firmino contributes much more to his team than just goals, however, so even if he's not always finding the back of the net he is still offering much to the cause. He knits things together in the final third, creating space and opportunities for his team-mates to make the most of.
While he may not be as potent as he was last season, he's still one of Liverpool's most important players.