Steven Gerrard has called on Chelsea to address their defensive problems when the January transfer window opens in less than two months' time.

Out of the Premier League's top 10, at the time of writing, only Aston Villa (17), who sit in 10th, have conceded more goals than the Blues (16). While Xabi Alonso's side only let in a single goal away at Sunderland on Sunday afternoon, that proved to be the difference in the match at the Stadium of Light.

Levi Colwill was deemed to have fouled Brian Brobbey inside the Chelsea box and referee Jarred Gillett pointed to the spot. Replays showed that Colwill and Brobbey had held of each other when entering the box, but Gillett believed it was more the Chelsea defender's foul than the Sunderland striker's.

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Enzo Le Fee stepped up from 12 yards and converted the winning goal in the first-half. Alonso then hooked Colwill at the half-time break before lambasting his side's defending after the match.

Speaking to reporters post-match, the Chelsea manager said: "Out of almost nothing, he [Brobbey] got a couple of chances. He got the penalty as well, but we have been preparing for that.

"No, [he’s] not unstoppable. He's stoppable, but only when you defend better than we did today."

Alonso was without Josh Acheampong for the defeat on Wearside due to a minor injury problem the Cobham graduate sustained the day before the trip. Wesley Fofana started alongside Colwill at the heart of the Chelsea defence, with Marco Palestra at right back and Pep Chavarria on the left-hand side.

Fofana and Colwill, who found it really difficult to cope with Brobbey on the day, have come under the most fire for their performances. Not just on Sunday, but for the majority of the season to date.

Gerrard, who came up against Chelsea's best-ever defence - the brick wall that Jose Mourinho used to field every week in the Blues' record-breaking 2004/05 season - during his playing days, hinted that the west Londoners need to sign at least three defenders, including "world-class" centre backs, as well as a left back.

Speaking on the latest episode of SkyBet's Overlap Daily, Gerrard was asked whether Chelsea's next batch of recruitment needs to be focused on defence: "100 per cent. Chelsea have good defenders. I really like Reece James when he's fit and available and he plays right-back. I think he's the best right-back in the country. Obviously, he's got his injury problems, which have been well documented.

"I really like Colwill, because he gives them nice balance and the left foot. They've got a fantastic goalkeeper now, who I've worked with. And I look at the midfield and the front line and think, that can compete.

"But with all due respect, I think for Chelsea to compete with Arsenal, City, Liverpool, and the top end of the Champions League, I think they need to find world-class centre-backs and a world-class left-back. That would be my opinion.

"Can I just relate that to when I played: Ashley Cole, John Terry, Ricardo Carvalho, Branislav Ivanovic? Now, that's a back four that can compete and proved that it can compete at the top end of the Premier League and the top end of the Champions League.

"If I look at Chelsea's back five now, I go Emiliano Martinez and Petr Cech, okay, not much in it. Martinez has proved he can win a World Cup and really perform at that high level. I think the Chelsea defenders have still got to prove themselves, that they can go and compete at the top end of the Premier League and also the top end of the Champions League.

"Because that back four that we played against at Chelsea, with Claude Makelele in front or Michael Essien in front, that was some base to a spine. They were top world-class players. I think for Chelsea to go to the next level, they need to recruit that."