He is worried that if Graham's goal at Swansea on Monday night kicks off a scoring spree it might encourage Gus Poyet to trigger the clause as Sunderland battle against relegation.
Bruce said: "We hope Danny is here with us for the season, but that is Sunderland's prerogative to call him back. He is on loan, so if the parent club come and call him, then so be it. Let's hope not."
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