Andre Villas-Boas revealed last week that he is looking to bring in two new faces during the January window, but warned that Chelsea will not overpay for players in an inflated transfer market this month.
Having had a bid accepted by Bolton Wanderers for England international defender Gary Cahill, negotiations between the club and the player's representatives are ongoing.
"Apart from a central defender, we might get one more player in but we're not sure yet," confirmed Villas-Boas. "It's always difficult.
"The top talent is normally cup-tied in the Champions League or in different domestic competitions and it's difficult for the selling club to make players available.
"It's normal that you struggle in the transfer market. Normally it's a market where you overpay a lot and that's what we don't want to do now."
Cahill's extravagant wage demands are understood to be the main sticking point, but after prolonged discussions the two parties are expected to reach agreement and a deal should be confirmed imminently.
That just leaves one question on all Chelsea fans' lips - who is the second Stamford Bridge signing Villas-Boas is talking about?
There has been no shortage of names linked with a move to west London, and as speculation continues to mount, GiveMeFootball identifies five players who could join the Blues' revolution.
Kevin de Bruyne [Genk]
The 20-year-old winger has been consistently linked with a move to Chelsea after almost signing for the club last summer.
An £8million price tag was deemed too much for the Belgian starlet, but Villas-Boas revealed his admiration for De Bruyne after the Blues' UEFA Champions League clash with Genk back in October, and could renew his interest this month.
"Chelsea are still interested in me and already have a plan in place for me," De Bruyne was quoted as saying last week. "Staying at Genk for another season is not an option for me."
Angel Di Maria [Real Madrid]
The 23-year-old Argentine winger has all the tools required to succeed in the Barclays Premier League, with his electrifying pace and trickery making him a menace for any defence.
Recent reports have suggested that Jose Mourinho would only be willing to sell Di Maria for around €40million, so Chelsea will face a fight to secure his signature.
"Di Maria can count on the love and appreciation of the club and we do not want to sell him," said Real Madrid sporting director Miguel Pardeza.
The 25-year-old Brazilian striker worked under Villas-Boas during Porto's treble-winning campaign last season, so the Portuguese tactician knows all about Hulk's ability.
However, the £83.5million buy-out clause written into his current contract is 'miles apart' from what Chelsea would be prepared to pay for the forward.
"I admit Hulk can't stay at Porto forever," his agent Teodoro Fonseca was quoted as saying this week. "That is football and at the moment the clause in his deal is decisive."
Joao Moutinho [Porto]
Another of Villas-Boas' star turns at Porto, the Portuguese international was strongly linked with a move to Stamford Bridge in the summer, before Chelsea turned their attention to Luka Modric.
The 25-year-old was a key figure for Porto after signing from Sporting Lisbon in 2010, and according to Lisbon-based newspaper A Bola, Moutinho will command a fee in excess of £20million if the creative midfielder is to link up with his former manager in west London this month.
Milos Krasic [Juventus]
The 27-year-old Serbian international has been heavily linked with a move to England, with Manchester United and Tottenham also having been credited with an interest alongside Chelsea.
Krasic is reportedly available on loan, something that could interest Villas-Boas with a view to a permanent move in the summer, after his agent ruled out the possibility of his client joining a rival Serie A club.
"There is still some interest in him from the Premier League," Vlado Borozan told notiziariosportivo.com. "I can rule out the prospect of Milos moving to another Italian team."