Chelsea boss Frank Lampard admits he needs to buy to fix their defensive problems.
Lampard lamented an absence of big players with the power and aggression to dominate in the air like his former team-mates Didier Drogba, John Terry, Michael Ballack and Gary Cahill.
"It is certainly something to take into account when you're looking at recruitment," he said.
"I really don't like to talk about my own playing days,' said Lampard. 'But we didn't work much on set pieces and there were a few reasons, mainly John Terry, Gary Cahill, Didier Drogba, Michael Ballack and Branislav Ivanovic. You would stick it in an area and they would defend it or score goals.
"Similarly with Liverpool, I remember a lot of talk about them and set pieces a few seasons ago. They were zonal and conceding a lot. They signed Virgil van Dijk and he heads everything that comes in the box.
"So there's a huge relation to personnel and if you don't have that size across the team, the main thing is trying to compete as hard as you can and making it difficult for other teams to score."
