Liverpool striker Rickie Lambert has admitted that he must continue to work on his fitness having failed to impress during his first competitive start for the club.

The England international, who joined the Reds from Southampton during the summer, was named captain of the side for Tuesday night's League Cup third-round encounter with Middlesbrough.

Lambert was replaced in the 74th minute at Anfield, however, following a frustrating night in which Liverpool eventually prevailed on penalties.

"I wasn't expecting it, and it was a great honour to lead the team. It was a nice surprise," BT Sport quotes the 32-year-old as as saying when asked about the captaincy.

"But forgetting about that, it was a strange game. I wasn't happy with my own performance, so that overshadowed the honour of being captain a little bit. I didn't feel as sharp as I want to feel. That's the main thing I want to look at going back into training.

"I want to get my match fitness up because obviously everyone knows I'm not playing every game so I have to adapt myself now. I think I'm going to have to do more so my fitness is up to the same level as everybody else."

Liverpool return to league action this weekend with a crunch meeting against Merseyside rivals Everton.