Prodl, 30, has been sidelined with a hamstring injury suffered during September's international break which has seen him miss his side's last four games. Kaboul meanwhile also missed a large chunk of last month after suffering thigh problem that forced him off in the 2-0 win over Southampton on 9 September.
Speaking at a press conference on Thursday, Watford boss Marco Silva explained Prodl remains a "doubt" for the visit of Arsene Wenger's side while Kaboul will have no chance of returning in time for Saturday's clash.
Silva meanwhile is yet to make a decision on Peru international Carrillo who will be assessed having only just returned from helping his country qualify for a World Cup playoff against New Zealand during the international break.
The 26-year-old rejoin the rest of his teammates in training on Thursday morning. "We'll see," said Silva. "Tomorrow we'll do the first session as he comes back this afternoon. We'll see his condition. I need to talk with him a little bit and after I will take my decision."
"It's not the first time it's happened. The game against Southampton, the same thing happened. I took the decision to then put him in the starting XI. I need to see how he is."
Isaac Success will be another absentee as he continues to recover from a knee injury suffered in training.
"We expect six to eight weeks," said Silva. "It's a knee injury, a problem he had in one session here. It was a normal situation and looked nothing special at that moment but after examinations, the problem is bigger and now we need to wait for him."
Arsenal travel to Vicarage Road having got their season back on track with four straight wins in all competitions.