Sunderland defender Phil Bardsley will miss the start of the Premier League season after undergoing an ankle operation.

Bardsley suffered the injury in a preseason friendly, meaning that manager Martin O'Neill will be without one of his regular defenders at the beginning of the new campaign.

The 27-year-old moved to Sunderland from Manchester United in 2008 and has made 130 appearances for the Black Cats.

In addition to Bardsley, Sunderland will also be without injured trio Stephane Sessegnon, Wes Brown and David Vaughan for the club's opening match against Arsenal on Saturday.