In demand: Steven Pienaar is a £3m target for Chelsea despite reports that Spurs have aglready agreed a deal to sign him
Sportsmail revealed in December that Tottenham were in pole position to sign the South African midfielder at the end of the season when his contract at Everton runs out.
And reports today suggest he may already have agreed a £70,000-a-week four-year deal at White Hart Lane.
However, it is understood that the player would prefer to leave in the January window and Tottenham's pursuit of David Beckham has allowed Chelsea to move in.
Carlo Ancelotti is desperate to add fresh faces to his squad as they look to shake off their league slump in time for the next phase of the Champions League.
Pienaar, 28, is eligible to play in Europe and would relish the chance to play for Chelsea who are willing to offer around £3m.
However, Everton do not want to lose one of their most influential players even if it does mean allowing him to go for nothing in the summer.
Everton manager David Moyes senses his side can kick on this year and holds out high hopes of success in the FA Cup where they play Chelsea in the next round.
Selling Pienaar would damage their chances as they would only be able to bring in loan signings or a small scale buy such as Adam Hammill of Barnsley.
Chelsea, though, believe Tottenham's pursuit of Everton captain Phil Neville may also muddy the waters for a prospective Pienaar move to White Hart Lane this month.
In the shop window: Steven Pienaar (right) helped Everton beat Tottenham last weekend
The relations between the two clubs are becoming strained and Everton would not countenance selling both players to Tottenham in January unless it was a ridiculous offer. That seems unlikely with Tottenham also in pursuit of a striker.
It leaves Chelsea in a strong position over Pienaar and they could even bargain with more suitable loan players in return.
Chelsea weighing up £3m move for wantaway Everton star Pienaar Arsenal and Chelsea ponder a move for Juventus' Legrottaglie as coverLampard hampered by failure to solve injury problems during Chelsea' slumpYakubu to play loan role at Leicester after agreeing switch from EvertonTottenham to press ahead with Neville move despite hands off warningCrocked King facing new woe as groin injury keeps Tottenham defender outClub-by-club guide to every Premier League transfer deal during JanuaryAll the latest Chelsea news, features and opinion
Explore more:People: Adam Hammill, Phil Neville, David Beckham, David Moyes, Carlo Ancelotti Places: London, Europe