Sunderland conceded six in its defeat to Everton and manager Sam Allardyce admits the team's defending has him worried.
Sunderland manager Sam Allardyce admits his side's defensive frailties are becoming a real concern after its defeat to Everton.
The visitors found themselves two goals down at Goodison Park on Saturday but clawed their way back to 2-2 thanks to Jermain Defoe and Steven Fletcher.
However, three goals in seven second-half minutes left Sunderland facing a mountain to climb before Arouna Kone scored his third of the match in the closing stages to seal a 6-2 victory.