There was a small piece of good news for the Italian boss, however, as defender Christian Kabasele returned to full training after two months out with a hip problem.
Striker Troy Deeney and midfielders Tom Cleverley and Abdoulaye Doucoure are all "very fatigued", according to Mazzarri, while Etienne Capoue, Valon Behrami and goalkeeper Heurelho Gomes are also doubts.
Roberto Pereyra (knee), Maurao Zarate (anterior cruciate ligament) and Ben Watson (groin strain) are all ruled out.
"It's our destiny," Mazzarri told a press conference. "Against Tottenham, we are always in an emergency.
"Britos was important because Kaboul and Prodl were injured and we do not have a defence now.
"We had one of the best games since I have been here on Tuesday (in the 2-0 win over West Brom), where the players played the way I like and I would have liked to have been able to play against Tottenham with a full team.
"But I told my players this morning that whoever is going to play Saturday has the chance to show that they deserve to have been playing in the past as well."
Watford's injury list has been one of the recurring themes of their season to date, but, despite it, the Hornets are still 10th in the Premier League standings.
"It's incredible. It's unusual and the injuries we have had this season are unusual injuries," Mazzarri added.
"I'm happy that despite all the injuries we are still going strong.
"It's one injury after the other. With Zarate, (Daryl) Janmaat, (Craig) Cathcart, it's difficult.
"I was told last year there weren't many injuries. But that's another reason I'm happy, as despite that, we're doing well."