Manchester United and England striker Marcus Rashford admits he knows very little about Perth Glory, and says it's too hard to predict whether Saturday night's game will turn into a thrashing.

United will start as the hottest of favourites when they take on a Glory outfit missing a host of their best players at Optus Stadium.

Glory skipper Diego Castro, striker Andy Keogh, forward Chris Ikonomidis, and defenders Matthew Spiranovic and Dino Djulbic are among the players who will miss the marquee clash.

Defender Jason Davidson also won't be there after leaving the club recently.

It remains unclear what strength side Manchester United will play in the game, but even their lowest-paid player will be leagues above what Glory have to offer.

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Pic special: Manchester United Perth press conference

Ole Gunnar Soskjaer had to glad hand WA Premier Mark McGowan and present him with a signed jersey in between fending off questions about his squad in Perth ahead of their clash with Glory.

Glory put up stiff resistance against Chelsea a year ago, only losing 1-0.

Rashford doesn't know what to expect from Glory.

"To be honest I don't know much about them," Rashford said.

"We know the facilities have been good here. We've had a good couple of days of training. Everyone is looking forward to that game, and I'm sure Perth are as well."

When asked if fans could expect a thrashing in the vicinity of 5-0 given the gulf of class between the two sides, Rashford replied: "It jus"t depends on fitness levels."

"They could be fitter than us, or we could be fitter than them.

"In pre-season that's probably the biggest challenge. But we know we've worked hard, so we are looking forward to the game."

The Red Devils will also face Leeds United in Perth on Wednesday night before departing Australia.

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In Pics: Manchester United train in Perth

All eyes were on Paul Pogba as his future at Manchester United remains uncertain, but the rest of the squad was also at training at the WACA as the Red Devils prepare for their friendly against Perth Glory.

United finished sixth in the English Premier League last season, and Rashford said the team were desperate to atone for that poor performance.

Seeing Manchester City win the EPL title and Liverpool triumph in the European Champions League have fuelled the desire of United's players.

"We never shy away from a challenge, so it's important that we face it head on," Rashford said.

"What's happened has happened. We have to move forward as a team."