Chelsea manager Carlo Ancelotti says he will consider signing a new defender if Alex fails to recover from knee surgery before the end of January.
However, the Italian is not planning to splash the cash any further in the transfer window, even though his squad has struggled to cope with injuries to key players in recent months.
Brazil international Alex was sidelined for up to eight weeks after undergoing a knee operation earlier in December.
His injury woes coincided with those of captain John Terry, forcing Ancelotti to use Paolo Ferreira as a temporary centre-back.
That move did not bring the greatest success to Stamford Bridge, with the Blues slumping to their worst home defeat for eight years against Sunderland.
But despite Chelsea's apparent lack of depth, Ancelotti is unwilling to indulge in a January spending spree.
"If I have to bet, I can bet the opposite," he said.
"Until 31st January, if we are sure that Alex will have resolved his problem, we won't need another defender.
"We have to wait to see his condition.
"We can think about things, a new defender, towards the end of January. That would be the only position."
And that player could well be English, according to the Italian, who added: "Obviously, if you take an English player, you don't have a problem with the culture, the language.
"Maybe they have advantages for this reason."
Ancelotti claims it is futile trying to sign a player to stand in for the likes of Frank Lampard, who will appear for the first time in four months in Monday night's clash at Arsenal.
The manager, who has already dismissed reports linking him with Tottenham playmaker Luka Modric, added: "In the market, there is no player capable of replacing Lampard."