The midfielder won't be playing on Thursday either, when Monaco host Borussia Dortmund in their UEFA Champions League quarterfinal.
Monaco leads 3-2 from the first leg in Germany, but their chances of advancing without Fabinho, who is serving a suspension, have dropped.
He's that important.
With him, Monaco has lost just once in 2017 and won 75 percent of its matches in all competitions this season.
His partnership with Tiemoue Bakayoko in midfield has been key as Monaco became Europe's most efficient attack.
A technically gifted holding midfielder who started at right back, Fabinho has also been contributing offensively, scoring 10 goals in 46 appearances.
"When he is not there, it makes a huge difference," said former Nice coach Eric Roy, now a TV pundit.
"In Monaco, they sometimes play with four attacking players at the same time. They need two midfielders covering a lot of ground. As soon as there is one missing, the team becomes a bit unbalanced."
Against Dortmund, Fabinho is likely to be replaced by Joao Moutinho, who partnered Bakayoko in the big loss to PSG.
Defender Djibril Sidibe is still out after an appendicitis operation while left back Benjamin Mendy has recovered from injury.
In addition to Fabinho's suspension, fatigue could also be a crucial factor against Dortmund.
Monaco, which progressed to the Champions League quarterfinals after starting its campaign in the third qualifying room, has already played 53 times this season.
The club is still involved in the French Cup and has played five matches over the past 15 days.
Fatigue and stress appeared to have an effect on Monaco's performance in its past two league games, when the French league leader had to rely on the individual brilliance of Radamel Falcao to secure scrappy but crucial wins.
"Every game will be like that until the end," manager Leonardo Jardim said. "If you don't play in the Champions League, you play once a week. And perhaps we win that match 3-0. If we progress in the Champions League, it'll be that type of scenario. We'll have to play with rage to find solutions and win."
Falcao's 26 goals this season confirmed his return to the highest level. Back to his best at the right time, he is expected to start alongside Kylian Mbappe, who has 15 goals in his last 15 matches with Monaco.
Following the explosions around Borussia Dortmund's team bus which led to the first-leg tie being postponed for a day, security has been reinforced in Monaco.
Monaco Interior Minister Patrice Cellario told L'Equipe newspaper that local authorities will make sure Borussia players feel in the principality.
Monaco authorities will also receive the support of about 350 French police officers in support of local security personnel deployed in and outside the stadium.
"WE'RE NOT DREAMERS"
Dortmund has no new injury worries ahead of its 100th Champions League match.
Apart from the long-term injured Mario Goetze, Andre Schuerrle and Sebastian Rode - as well as Marc Bartra, who was wounded in the bomb attack on the team bus - manager Thomas Tuchel has a full contingent to choose from.
"The team has been outstanding over the past week," Dortmund chief executive Hans-Joachim Watzke said of the side's reaction to the attack.
Dortmund responded to its loss to Monaco with a comprehensive 3-1 defeat of Eintracht Frankfurt in the Bundesliga. The players held Bartra's shirt to fans after the game.
"We're not dreamers. We know that the chance is small, but there is a chance," Watzke said.