Manchester City manager Pep Guardiola has refused to rule out signing a third defender this summer, after already spending around £125m on bolstering his options at the back.
The Spaniard said City are on the hunt for another centre-back before the transfer window shuts at the end of August.
The Manchester club have already assembled the most expensive defence in history after completing deals worth around £50m for full-backs Benjamin Mendy from Monaco and Kyle Walker from Tottenham, as well as a £26m move for Real Madrid right-back Danilo.
Four of the five most expensive defenders ever bought are now contracted to Etihad Stadium, with Walker and Mendy ranked just ahead of John Stones and Eliaquim Mangala, signed for £50m and £42m respectively.
Yet with City looking to offload Mangala this summer, Guardiola is looking to strengthen his options in the middle of defence.
"Of course I'm happy with John [Stones], Vinny [Kompany] and Nico [Otamendi] but we're going to see. We don't have too much more to spend," said Guardiola.
"We've spent a lot and the market is so, so expensive in the last few years. But we're going to see. If the market gives us a chance, we're going to try. But if not, we'll go with our guys."
City play a friendly in Nashville tonight against fellow Premier League side Tottenham, the only club yet to sign a player in the summer transfer window.
Yet manager Mauricio Pochettino has assured fans that the lack of transfer activity is not a signal of a lack of ambition at the club.
"Our moment will arrive," said Pochettino ahead of the game.
"We are calm because our squad is competitive. We have a plan. We have a very clear idea of what we want.
"There are a lot of rumours about the big sides spending money and it looks like Tottenham is not ambitious.
"I want to tell our fans 'don't be worried' because we will move in the market."