Summer signing Marcal is on course to be involved against Leeds on Monday having been one of the few players who was still working at Compton over the international break.
The 31-year-old Brazilian missed the games against West Ham and Fulham but has made positive strides over the past couple of weeks, as Nuno said: “We have players that came from national teams with problems that we have to deal with, assess and manage.
“Fortunately, players that were here, like Marcal, are starting with the team already, the first sessions with the team.
“It’s about trying to balance everybody so that we can have a full squad in these moments.”
Marcal’s return from a calf problem is a boost for Nuno, and the boss is hoping for more good news after the latest round of Premier League coronavirus testing.
He had 16 players away on international duty and, thanks to a new system put in place by the club, they were all able to be tested at Compton on Thursday.
After getting the results from those, they were able to train normally as a group.
Now, they await the results from the Premier League tests to fully ensure those who went away with their countries – Portuguese players Rui Patricio, Nelson Semedo, Ruben Neves, Joao Moutinho and Daniel Podence having been in the same squad as Cristiano Ronaldo, who tested positive – can feature at Elland Road.
“We’ve been tested (Friday), and for the players who were arriving (back from their countries), we have a new system of testing,” added Nuno.
“That allowed us not to make mistakes when the players came back from their national teams.
“So, when they join the group, they have previously been tested here at Compton.
“Now, let’s wait for the results from (Friday) morning. We’re still waiting but, for now, everybody is healthy.
“We were worried about everybody that was involved in national teams, changing environment.
“In the national team of Portugal, there were cases. But like I say, our players were tested on (Thursday) and I’m positive Portugal’s medical team made all the measures and took the care necessary to avoid contact more than they should.
“We have to realise there is an increase in infection rates all over the world and will affect everybody.
"We’ve had our results now it’s more time, probably Sunday morning, we will have the final results.”