The Wellington Phoenix were left with just five players at training last week following a Covid-19 outbreak in the squad.
Coach Ufuk Talay revealed that 17 players contracted the virus in Australia, along with two staff members.
Talay, who was fortunate to be one of the few to not test positive for the virus, said the players have now recovered and the team had their first full training on Monday.
The Phoenix haven't played since beating Melbourne City on penalties in the FFA Cup quarter-final on January 5, with their two A-League games against Brisbane Roar and Perth Glory postponed.
Talay said players will be eased back into training ahead of their next scheduled game against Western United in Wollongong on Friday.
"We've had dribs and drabs of players coming out of isolation into training and we've had to modify what they were doing because we've never lived through this previously. We don't know what would happen when they come back from having Covid. So, we're just being mindful of trying to build them back up again," Talay said.
"We're trying to build them up slowly. Just get some load in the legs and also a bit of oxygen in the lungs. But you can see some players are fatigued a lot quicker at the moment, so it's not going to be easy to build them back up to get them to a certain level.
"But at the same time, the league's going to continue and we need to expose them as much as we can to be able to train and play at that level. We'll take it day by day and every individual case is different. So, we'll just look at the players and how they're dealing with it."
Talay said he hoped the worst is behind them and that no further disruptions would occur, with the Phoenix now having to play catch-up.
"Hopefully this is the last of it but we'll take it day by day.
"It's not easy for APL to schedule these things, it comes down to what teams are coming out of Covid, what teams are available to play and what stadiums are available on what dates, so I know they're doing their best.
"Once we have a clear idea of what it looks like next, it gives us an opportunity to prepare and plan as best we can."
Meanwhile, the Phoenix's two new signings, Gael Sandoval and Scott Wootton, could both make their debuts on Friday.
Experienced English defender Wootton, who played four games for Manchester United under Sir Alex Ferguson, arrived in Australia last week and trained with his new teammates for the first time on Sunday.
"Scott had his first session yesterday with the group and he's still recovering from his long journey from the UK, but we'll slowly build him up and see how he pulls up in the next few days and see if he's available to play on Friday," Talay said.
Talay also confirmed goalkeeper Oli Sail and forward Oskar van Hattum remain sidelined with injuries.