Schwarzer was crucial in Australia's qualification campaign to reach the 2014 World Cup finals in Brazil and, at the end of last season, the veteran goalkeeper would have been widely considered the first name on the team sheet for Socceroos head coach Holger Osieck.

But having left English Premier League club Fulham after they would not guarantee him first-team football, Schwarzer signed a one-year deal with Chelsea.

It seemed a strange move as no one expects Schwarzer to dislodge Petr Cech as Chelsea's leading goalkeeper, while it could open the door for the likes of Borussia Dortmund's Mitch Langerak and Club Brugge's Mat Ryan to nick the Socceroos' number-one shirt for Brazil.

Speaking to Triple M in Adelaide on Thursday, Schwarzer conceded his move to Chelsea might have confused Socceroos fans but claimed he has no concerns about a lack of game time ahead of, what will be, his third World Cup.

"I absolutely understand people's concerns," Schwarzer said. "It was obviously a big decision for me to make.

"I thought long and hard about it, had conversations with plenty of people and, one in particular, who is the manager of Chelsea Football Club, which in the end swayed me to the decision I made.

"I'm confident I will have played enough games by the end of the season to be in the best possible shape to represent Australia at a World Cup. Only time will tell but I still believe that will happen."

Chelsea manager Jose Mourinho, who has returned to Stamford Bridge after stints in charge of Inter Milan and Real Madrid, has already confirmed Schwarzer will be back-up to Cech.

But Mourinho claimed last month the 40-year-old Australian is the perfect option to push Cech and cover for the Czech Republic international if he gets injured.

"We need competition for him (Cech), motivation for him, security and I think Schwarzer is perfect for that," Mourinho said.

"He (Schwarzer) has experience, has spent his whole career in the Premier League, so it's his natural habitat.

"Getting Mark on a free transfer, we have the goalkeeper to complete our set of goalkeepers."