The fear of players testing positive for COVID-19 as they travel to Australia will be keeping Socceroos coach Graham Arnold awake over the weekend as his squad assembles in Melbourne ahead of crucial World Cup qualifiers.
Arnold has named a 25-man squad for next week's clash with Vietnam at AAMI Park and an away date with Oman in Muscat on February 1.
The return of star midfielders Aaron Mooy and Tom Rogic headline 10 changes to the squad from that picked for the previous international window against Saudi Arabia and China.
Injuries, COVID-19 and other factors have forced Arnold to alter his lineup.
Centre-back Harry Souttar is out after damaging an ACL against the Saudis, left-back Callum Elder is also injured while winger Awer Mabil has fallen out of favour with Danish club FC Midtjylland and is recovering from a bout of COVID-19.
Arnold is wary he could yet have to make further alterations as players travel from all over the globe to Australia in the coming days.
"We're picking this squad today but the fingers will be crossed all weekend that no-one goes down with COVID right through ... players coming across from Europe and here in Australia in the A-League," Arnold said.
"They're all challenges that we've got to get on with and I've picked a squad that I believe is strong squad. A squad that's healthy and ready and it'll add more depth in the long run."
As well as key duo Mooy and Rogic, Arnold has also called up uncapped trio Joel King, Kye Rowles and Marco Tilio.
All three were part of Arnold's Olyroos squad in Tokyo last year and are three of nine Australian-based players in the team.
Melbourne City's Tilio starred at the Olympics, including a wonder strike in the 2-0 win over Argentina, and played a big role in Patrick Kisnorbo's team winning last season's A-League Men's title.
"I've got a lot of belief and a lot of faith in those kids," Arnold said.
"I know they can do great things. It's more about consistency and I've seen that this year with them.
"Marco gives you a complete X-factor, either if he starts or comes off the bench where he's one of those players that Australia doesn't have a lot of, that can change a game with one action."
German-based Adjin Hrustic, suspended for the Vietnam game, will link up with the squad in Doha.
After slipping out of the two automatic qualifying positions with a loss and two draws in their past three qualifiers, Arnold knows the Socceroos cannot afford any more slip-ups if they're to avoid having to try to reach Qatar 2022 via a continental playoff.
"As I will say to the boys when they turn up here, that's all in the past. That's last year," Arnold said.
"We are here today, where we have everything in our own hands.
"We have four games that we have to play between now and qualifying for Qatar and I expect to win four games."
SOCCEROOS SQUAD TO FACE VIETNAM AND OMAN
Aziz Behich, Brandon Borello, Martin Boyle, Milos Degenek, Mitchell Duke, Craig Goodwin, Rhyan Grant, Adjin Hrustic, Jackson Irvine, James Jeggo, Fran Karacic, Joel King, Mathew Leckie, Jamie Maclaren, Ryan McGowan, Riley McGree, Connor Metcalfe, Aaron Mooy, Andrew Redmayne, Mathew Ryan, Tom Rogic, Kye Rowles, Trent Sainsbury, Marco Tilio, Danny Vukovic.
