The two Brazilians are set to participate in Selecao's upcoming friendlies against Ghana (September 23) and Tunisia (September 27).
Fabinho posted a picture of himself, Antony, and Atletico Madrid forward Matheus Cunha enjoying the international break.
Antony responded to the post by saying:
"You are the best."
It has been a difficult start to the season for Fabinho, whose Liverpool side have faltered both domestically and in Europe.
The Anfield outfit sit eighth in the league having won just two of their opening six league games.
They have had a similar ride in the Champions League where they suffered a demoralizing 4-1 defeat to Napoli on September 7.
Liverpool do sit second in Group A following a vital 2-1 win over Ajax on September 13.
The former AS Monaco midfielder's performances have been criticized as he has failed to continue the impressive form he showed last season.
Meanwhile, Antony kickstarted his Manchester United career with a debut goal against Arsenal in a 3-1 win.
The winger became Manchester United's most expensive signing when the Red Devils paid Ajax £85.5 million to lure him to Old Trafford.
Both Fabinho and Antony will be looking to achieve FIFA World Cup glory with Brazil when the tournament kicks off in November.
Brazil are the current World Cup record holders, having won the tournament on five occasions.
They are among the frontrunners to win this year's competition with talent such as Neymar, Antony and Vinicius Jr flourishing.
Manchester United and Liverpool to compete for top four
It appears that Liverpool will not be challenging for the Premier League title if their current form continues.
The likelihood is that they will face a battle with the likes of Erik ten Hag's men for a top-four finish.
The departure of Sadio Mane to Bayern Munich has left the Merseysiders at a loss from an attacking perspective.
The £80 million signing of Darwin Nunez is yet to pay dividends and Jurgen Klopp's side's midfield has looked extremely lackluster.
Meanwhile, United are being transformed by Ten Hag and have won four games on the trot in the league.
It is still a season of adaptation for the Red Devils, who have been boosted by the arrivals of the likes of Antony, Christian Eriksen and Lisandro Martinez.
The two Premier League heavyweights have already faced off at Old Trafford on August 22 with Manchester United being 2-1 victors on that occasion.