The Socceroos legend, grounded for the last two months, has three club games in a week to impress new national team boss Bert van Marwijk and make the Dutchman's squad for March friendlies with Norway and Colombia.

And while van Marwijk might just select Australia's all-time leading scorer on reputation alone, there's no doubting the 38-year-old needs game time at club level if he's to make an impact in Russia for the Socceroos.

Van Marwijk is due to name an extended 30-man squad - with the potential for a few more - in the first week of March.

Before then, Cahill has the potential to play in 270 minutes for new club Millwall.

The Lions have league fixtures with Birmingham on Sunday, Sheffield Wednesday on Wednesday, and Burton Albion next Sunday (all times AEDT) in a typically busy week in England's second tier.

The bad news for Cahill is that his coach doesn't think he's ready to start matches yet.

Neil Harris told BBC radio this week that Cahill, who left Melbourne City in early December, was a long way off full fitness.

"He needs a lot more minutes on the training pitch and in behind closed doors games to really get him up to speed," Harris said.

"If he gets up to speed in the next few weeks and is ready to start a game then fantastic.

"If he is not, then he has got a massive part to play from the bench."

Cahill spent two months over summer without a club after agreeing to a contract termination from City

Despite his stated aim for more game time, Cahill opted for a personal training regime as the A-League continued on without him.

Without Cahill, City were left without a senior striker in the squad when Ross McCormack was injured.

That led to criticism that Cahill was chasing a final pay day in the Middle East, Europe or the USA - or had other plans.

Having landed back in south London, Cahill has three matches before van Marwijk's first squad, and 15 games left in the season, to re-capture club form that will take him to Russia.

He hasn't scored a league goal since April last year, when he netted a brace in Perth in a 5-4 loss to the Glory.

Cahill's last goals of any form came in October - a crucial double to ensure Australia snuck past Syria in their Asian World Cup qualifying playoff.

With just over two hours of club football under his belt since City crashed out of the A-League finals 10 months ago, it's easy to see why Millwall's run-in looms large for the livewire forward.

Australian Associated Press