Phil Bardsley admits Sunderland need to be at their best when they host Arsenal on Saturday.The Gunners have been in fearsome form in front of goal this season and will be keen to continue that trend at the Stadium of Light.Bardsley, who will form part of a back four directly in the firing line, admits as much, but the combative full-back feels Steve Bruce's side are capable of springing an upset."It's going to be a great challenge because they're a tremendous side Arsenal, we know that," he told the Sunderland Echo."They don't often lose games. You go into games against them with no-one expecting you to do anything against them."But if we go into the game with the same sort of attitude as we've shown against other big guns, like Manchester United and Liverpool, then there's no reason why we can't get something out of the game."I suppose Arsenal are the ultimate test at the moment, if you're a defender, because of the fact they're such a good goalscoring side."They've got great movement and great quality players, they love to go forward and they love to do it with pace."But that's why we're here. That's why we're in this division, to test ourselves against challenges like that and to stand up to them and even overcome them."If we show the right attitude and produce our best football then we can produce an upset."