McEachran has yet to start a Barclays Premier League game but Ancelotti was impressed by his performance during last weekend's 7-0 FA Cup win against Ipswich.
The 17-year-old injected energy and creativity into a midfield which has struggled badly through a run of just two wins in 11 league outings.
Under pressure: Michael Essien's (right) place is under threat
It would be a big call to drop Essien, a £24million signing from Lyon five years ago and a senior dressing room figure, but he has not recaptured top form since returning from a second serious knee injury in two years.
Ancelotti said: 'My job is to choose the best team to play the game.Maybe sometimes there are some players who are not in good condition toplay. This does not mean they are not important. I had some fantasticplayers in the past and they did not play every game.
'McEachranis ready to start in the Premier League. He has confidence, personalityand he is strong. You look at him and think he won't be strong in thetackle but he was against Ipswich. He doesn't lack anything.'
New kid on the block: Josh McEachran impressed in the 7-0 drubbing of Ipswich
Didier Drogba and Florent Malouda also find their places in doubt against Blackburn today after being rested against Ipswich.
Asked whether he was willing to wield the axe and risk a dressing-room backlash, Ancelotti replied: 'Yes, why not?'
The Italian is cautious by nature and has always valued experience but admits he is torn. 'I have doubts up front and in midfield,' he added.
The Blues withdrew from the chase for Steven Pienaar because of his £70,000-a-week wage demands. Spurs last night offered £2m for the South African and were awaiting Everton's response.
No stranger to tough decisions: Ancelotti
'We are thinking about central defence,' said Ancelotti in relation to signings. With injured duo Alex out since November and Yuri Zhirkov suffering setbacks, Chelsea could be forced into buying.
Benfica's David Luiz, 23, is the preferred choice but the clubs are at loggerheads over the price. Others linked include Bolton's Gary Cahill, Neven Subotic of Borussia Dortmund and Atletico Madrid's Diego Godin.
Having slid to fifth, Chelsea will be tempted to spend to reduce the risk of finishing outside the top four.
'This club need to play in the Champions League,' said Ancelotti, 'I'm sure we will but I don't like to promise.'
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Explore more:People: Michael Essien, Didier Drogba, Gary Cahill, Yuri Zhirkov, Carlo Ancelotti Places: Lyon