Sunderland boss Martin O'Neill admits he was disappointed with defeat to Leicester City.

Sunderland went down to a 72nd-minute goal from substitute Tom Parkes in the Midlands following the midweek draw at Derby.

"We have plenty to work on," O'Neill told "There are a number of areas which need strengthening.

"Today, the second half was played at a better tempo than most of Wednesday night [at Derby].

"It's Leicester's final game of the pre-season too before they kick off and I think the game had more of a competitive edge to it."