Sunderland manager Martin O'Neill has admitted that his side struggled to keep up with Liverpool following their 3-0 reverse at Anfield.

The Black Cats boss conceded that his players "ran out of steam" off the back of a hectic festive schedule and were outclassed.

"Liverpool were too strong for us and deserved to win the game," he told reporters. "It looked as though we ran out of steam out there tonight.

"We started off very brightly indeed and had Liverpool on the back-foot, but once they got their goal they opened us up and exploited us."

A Luis Suarez double and a Raheem Sterling strike sunk Sunderland in a one-sided encounter that left O'Neill's outfit in 14th place in the table.

"Luis Suarez is a top quality footballer and he was a handful tonight." O'Neill added.

"Perhaps it was a case of a bridge too far, we've played four games in 12 days and we've got one of the smallest squads in the Barclays Premier League.

"We've had some big games as of late and maybe in terms of recovery we just haven't got that ability to switch things around as we would like to."

Sunderland's next match is an FA Cup third-round tie away to Championship outfit Bolton Wanderers.