The English top-flight returned on Wednesday after over three months in a hiatus owing to the coronavirus pandemic.
Success, 24, who signed from Granada on July 1, 2016 for a record transfer fee, has played only five times in the Premier League this term without a goal.
His injury means he will be added to a growing list of Watford players to miss out on the Vicarage Road showdown, including Gerard Deulofeu and Daryl Janmaat.
During Thursday’s chat with the club website, Pearson confirmed the development without indicating the length of time he will be absent.
“Isaac Success has ruptured his Achilles. Deulofeu won’t be available this season, he’s got a serious knee injury with his cruciate. Janmaat won’t be available either,” he said.
“But everybody else more or less is available. We’ve tried to prepare the players at a pace which really does reflect very much where they are themselves.”
“The players came back in good condition,” he continued.
“We had players who re-joined at different stages based on their own feelings, but during that time some of those players had one-to-one sessions so they were integrated back in.
“We’ve at least had the last two weeks where the squad has really been together, and it’s allowed us to work at a pace where we think we’re as prepared as we can be given the circumstances.”
Injuries could become more frequent due to the break in the season, but manager Pearson has expressed his satisfaction with how rapidly his men have returned to fitness.
“We have to understand there might be a greater injury risk,” he added.
“Having said that, I’ve been delighted with how the players have both returned to training and embraced the need for us to get back to a game situation as quick as possible given the circumstances we’re working in.”
Watford are in the relegation zone and have 27 points from 29 league outings so far, and victory over Brendan Rodgers’ men will see them move up the log.