Bernard Foley is in doubt for the Waratahs' opening Super Rugby match against the Reds after sustaining a shoulder injury in Friday's pre-season fixture.

The Tahs suffered a 40-35 defeat against the Highlanders in Queenstown and also lost their first-choice flyhalf.

Waratahs coach Daryl Gibson said Foley's injury could keep him out of action for three to four weeks. 

'He sustained a shoulder injury, so we're unsure how limited he's going to be in the next few weeks,' Gibson said. 'But until he's assessed properly [we won't know]. At the moment, he's in doubt in for next week.'

Kurtley Beale will wear the No 10 jersey if Foley fails to recover in time.

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