Sunderland boss Sam Allardyce has claimed that Jermain Defoe is a "critical" player for the Black Cats as they attempt to escape the Premier League relegation zone.

Defoe, 33, has scored 10 league goals for Sunderland this season, including one against Liverpool in their 2-2 draw at Anfield last weekend.

Ahead of Saturday's clash with Manchester United, Allardyce spoke about the importance of the team "providing chances" for their leading scorer, but the experienced boss also admitted that his side need to improve defensively.

"Providing chances for Defoe is critical for us. But our first major problem is that we haven't kept a clean sheet in nine matches," Allardyce told reporters.

"We need to start putting a zero against us in games and if we start doing that we'll win more matches. If we win more matches, we'll get out of trouble."

The Black Cats, who have only won five of their 25 league games this season, currently sit 19th in the Premier League table - four points behind 17th-placed Newcastle United.