Sunderland boss Sam Allardyce has revealed that he may be forced to alter his formation due to his side's injuries.
The Black Cats have successfully deployed a 3-5-2 system in their back-to-back wins over Crystal Palace and Stoke City that has helped lift them out of the relegation zone.
However, injuries to Sebastian Larsson and Jermain Defoe ahead of their trip to Arsenal have made Allardyce reconsider his strategy against the Gunners.
He told reporters: "Yes we'll stick with three at the back because the more you can work on it and keep the one system, then the better it gets.
"Obviously at this moment in time, it seems to suit the team, but if you get injuries in certain areas, then we might have to change. But while the team is playing well in that system and producing results, then you stay with that.
"Our injury scenario means we'll have to tweak it because we haven't got Seb or Jermain Defoe. Other players will have to step in and do the business."
Sunderland face Arsenal at the Emirates Stadium on Saturday.