The 27-year-old Boro striker, who put in an impressive performance in Australia's 2-1 win over Wales recently, had to be replaced at half-time of Sunday's English Championship game.

McDonald had felt tightness in his hamstring early in the contest, before Boro boss Tony Mowbray opted to err on the side of caution whilst re-shuffling his side who had trailed at the break.

"I don't think it's a bad one, I'm hoping it's only a slight strain,” Mowbray told reporters after the game. “It was easy for me to make a tactical chance and match them in midfield.”

However, Mowbray hinted McDonald may miss a game or two, when he discussed the possibility of Middlesbrough bolstering their attacking options.

"We're looking hard to try to find some competition in the forward areas of the pitch and there's an urgency to do that with Scott's injury," he said. "We had two fit strikers at the club and we've got one now.”

Socceroos coach Holger Osieck is to name the Australia squad for next month's qualifiers against Thailand and Saudi Arabia early this week.

Australia are due to face Thailand on September 2 in Brisbane, before travelling to Saudi Arabia for a clash on September 6.