Arsenal boss Arsene Wenger admits he needs to consider the balance of his overall team when selecting a centre-half pairing.
The Frenchman has plenty of options in defence now Thomas Vermaelen, Johan Djourou and Sebastien Squillaci are fit to challenge this season's main partnership of Laurent Koscielny and Per Mertesacker.
"The balance is vital," Wenger told Arsenal Player .
"In fairness though, I must say that all the three can play with each other. Koscielny and Vermaelen can play together and Mertesacker can play with Vermaelen and Koscielny. It gives us a bit of an opportunity to rotate a bit when needed and people are tired.
"Ideally, Vermaelen will play on the left [of the centre-back pair]. But Koscielny can play on the left as well so we have a good potential and balance there. I think that all the three can play at any moment, and we still have Djourou and Squillaci as well.
"People wanted us to buy a centre-back so much and then suddenly you realise we have plenty."